fbpx
Wikipedia

Comet Kohoutek

January 01, 1970

Not to be confused with the short-period comet 75D/Kohoutek.

Comet Kohoutek (formally designated C/1973 E1 and formerly as 1973 XII and 1973f)[c] is a comet that passed close to the Sun towards the end of 1973. Early predictions of the comet's peak brightness suggested that it had the potential to become one of the brightest comets of the 20th century, capturing the attention of the wider public and the press and earning the comet the moniker of "Comet of the Century". Although Kohoutek became rather bright, the comet was ultimately far dimmer than the optimistic projections: its apparent magnitude peaked at only –3 (as opposed to predictions of roughly magnitude –10) and it was visible for only a short period, quickly dimming below naked-eye visibility by the end of January 1974.[d]

C/1973 E1 (Kohoutek)
Comet Kohoutek on 11 January 1974 as seen from Catalina Observatory
Discovery
Discovered byLuboš Kohoutek
Discovery date18 March 1973
Designations
Pronunciation/koʊˈhuːtɛk/
ko-HU-tek
/koʊhoʊtɛk/
ko-ho-tek[a]
1973f, 1973 XII
Orbital characteristics[4]
Epoch 24 December 1973 (JD 2442040.5)
Observation arc1.24 years (594 observations)
Aphelion98000 AU (inbound)
3700 AU (outbound)[4]
Perihelion0.1424249 AU[5]
Eccentricity0.999997 (inbound)
0.99992 (outbound)[4]
≈11 million yr (inbound)
≈ 80 thousand yr (outbound)[4]
Inclination14.30426°
258.48953°
28 December 1973[5][6]
37.79761°
Earth MOID0.029043 AU (4.34 million km)[6]
Physical characteristics
Mean diameter
4.2 km (2.6 mi)[7]
Albedo0.67[7][b]
–3 (1973 perihelion)
0 (peak for ground observers)[8]
5.8 (total)
9.5 (nucleus)

The comet was discovered by and named after Luboš Kohoutek at the Hamburg Observatory on 18 March 1973; Kohoutek had been searching for Biela's Comet and had serendipitously discovered his eponymous comet while reviewing photographic plates for a different object. The comet was discovered farther away from the Sun than any previous comet. Conventional practices for predicting comet brightness led to generous projections of Comet Kohoutek's luminosity towards the end of 1973 and the beginning of 1974, leading to great anticipation within both scientific circles and the general public. Comet Kohoutek reached perihelion on 28 December 1973. Though the comet was then at its brightest, it could only be observed by scientific instrumentation and astronauts on Skylab. For most ground observers, Kohoutek only reached as bright as magnitude 0 when it emerged from the Sun's glare in January 1974. It quickly faded beyond naked-eye visibility later that month and was last observed in November 1974. Due to its underwhelming brightness after intense publicity, Kohoutek became synonymous with spectacular disappointment.

Because of its early detection and unique characteristics, numerous scientific assets were dedicated to observing Kohoutek during its 1973–74 traversal of the inner Solar System, making Kohoutek the most well-studied comet at the time; the resulting findings significantly advanced the understanding of comets. The identification of larger and more complex molecules emanating from Kohoutek alongside related but simpler chemical species confirmed the hypothesis that comets were composed of larger molecules that dissociated into simpler products. The significant presence of gasses and plasma expelled from Kohoutek supported the longstanding "dirty snowball" hypothesis concerning the composition of comet nuclei. The detection of water,[e] methyl cyanide, hydrogen cyanide, and silicon in Kohoutek were the first time such chemical species were observed in any comet. Its underwhelming display challenged longstanding assumptions regarding the light curve of similar comets entering the inner Solar System.

Kohoutek's highly eccentric orbit preceding its 1973 perihelion suggests that it may have been formed early in the formation of the Solar System or it may have originated from a different planetary system. Its orbital period may have been initially in the order of several million years, or its 1973 apparition may have been its first trek into the inner Solar System. Its nucleus has an estimated average radius of 2.1 km (1.3 mi).[7]

Discovery edit

 
Luboš Kohoutek, eponymous discoverer of Comet Kohoutek, at the mission control center at Johnson Space Center speaking with the astronauts of Skylab 4 during the passage of the comet in January 1974

The comet was discovered on 18 March 1973 by Czech astronomer Luboš Kohoutek after reviewing twice-exposed photographic plates taken by the 80 cm (31 in) aperture Schmidt camera at the Hamburg Observatory in Bergedorf on 7 March and 9 March. The object remained evident and was displaced slightly towards the west-northwest in the latter plate, confirming that it was moving against the background stars and not a transient or erroneous feature.[11][1]: 1  Upon discovery, the comet had an apparent magnitude between 15.5 and 16 and lay in the constellation of Hydra; Kouhoutek described the comet as initially "diffuse with central condensation".[12][13] The comet was located near the orbit of Jupiter around the time of discovery, 4.7 astronomical units (AU) away from the Sun and 4 AU from the Earth.[14][11] As a result, the comet was moving very slowly towards the west-northwest at around 0.2° per day.[15] Based on subsequent orbital calculations, the discovery of the comet occurred roughly seven months before perihelion.[16] The discovery of a comet at such large distances and long leadtimes before their perihelia was unprecedented;[17][18]: 12  at the time comets were rarely discovered at such large distances from the Sun as most were too faint to be detected.[19] Kohoutek transmitted his findings to the Central Bureau for Astronomical Telegrams on 19 March, leading to the announcement of his discovery in circular 2511 of the International Astronomical Union. It was the sixth comet discovered in 1973 and thus given the designation 1973f.[12][1]: 3  Due to increasing public attention towards the comet, the comet was also named Comet Kohoutek in honor of its discoverer Luboš Kohoutek.[1]: 3 

The comet's discovery was serendipitous: beginning in 1971, Kohoutek had been searching for Biela's Comet, which had not been observed since 1852. Using the Hamburg Observatory's Schmidt camera, the initial search in October and November 1971 found 52 minor planets in a roughly 180-square-degree region of the sky. Preliminary orbits were determined for 35 of these newly-found objects, of which 15 were targeted for observation between January and April 1973. The 7 March photographic plate was intended to feature one of the objects, main-belt asteroid 1971 UG,[f] but instead captured Comet Kohoutek.[12] Comet Kohoutek was later precovered on a photographic plate taken on 28 January, exhibiting a similar brightness as during its discovery and a heliocentric distance of 5.2 AU.[14][15] The plate was also taken in pursuit of 1971 UG.[15] The comet was the second discovered by Kohoutek in 1973; the first had been discovered on 28 February during the same search for Biela's Comet and was also found on a photographic plate that was intended to contain another of the newly discovered minor planets.[12][g]

Orbit edit

 
The orbits and timings of Comet Kohoutek near its perihelion (in red) and the Earth (in blue)

Orbital elements for Comet Kohoutek were calculated by British astronomer Brian G. Marsden soon after the comet's discovery, using photographic plates taken of the comet on 7 March, 9 March, and 21 March.[12] These calculations suggested that Kohoutek had a nearly parabolic orbit lying close to the ecliptic with an eccentricity between 0.9999 and 1 and an inclination of 14.3°. Such an orbit meant that the comet would approach very close to the Sun, with perihelion occurring on 28 December 1973 at a distance of only 0.14 AU.[5] The close perihelion and the comet's brightness upon discovery were analogous to other comets that had become very bright. The calculated orbit also suggested that Kohoutek's close pass of the Sun could be its first traversal of the inner Solar System.[14][13] Marsden's calculated orbit placed Kohoutek's initial semi-major axis at 50,000 AU.[22][4] Alternatively, Kohoutek may have had an orbital period of 4 million years before experiencing the gravitational perturbations from the Solar System's planets, which would make Kohoutek a long-period comet.[23] This idea was supported by Stephen P. Maran, the head of NASA's efforts to study Kohoutek. Maran believed that the comet initially had a perihelion farther out than the orbit of Jupiter until it was gravitationally perturbed by a passing star, lowering its perihelion to within the orbit of Mercury and its orbital period to 4–5 million years; additional gravitational interactions between the comet and the planets would have shortened the comet's orbital period further to about 75,000 years.[24][4] The closest approach of Kohoutek to Earth occurred on 15 January 1974 and be no nearer than 0.8 AU, preventing the resolution of its nucleus via Earth-based instruments.[25][26]

Both the Minor Planet Center and the JPL Small-Body Database list Kohoutek as having a hyperbolic trajectory when it was near perihelion,[5][6] but the orbit became bound to the Sun by 1978.[27] The comet is not expected to return for about 75,000 years.[4] Some of the meteoroids ejected by Kohoutek during its initial approach, particularly those with diameters no smaller than 0.2 mm (0.0079 in), were placed into stable orbits around the Sun.[28]

As seen from Earth between 1973 and 1974, the comet took a southeastward path across the sky similar to Comet Halley's path between 1985 and 1986. The visibility of the comet was most favorable to observers in the Southern Hemisphere and the tropics. It was in the evening sky from the time of its discovery to the end of September 1973, after which the comet became a morning sky object. After being positioned in Hydra upon the time of discovery, Comet Kohoutek moved across the constellations of Sextans, Leo, Crater, Corvus, Virgo, Libra, Scorpius, and Sagittarius by the end of 1973. Kohoutek was near the boundary of Sagittarius and Ophiuchus during perihelion when it was visually separated from the Sun by only 0.5°. In 1974, the comet moved across the constellations of Capricorn, Aquarius, Pisces, and Taurus.[11][13] As of 2022, comet Kohoutek is about 74 AU (11 billion km) from the Sun in the constellation of Gemini.[29] It is currently receding from the Sun at 4.8 km/s (11,000 mph).[29]

Structure and composition edit

 
False color image of Comet Kohoutek as photographed with a far-ultraviolet electrographic camera during a Skylab spacewalk on 25 December 1973

Kohoutek's highly eccentric orbit and possible lack of prior planetary or solar interactions suggest that the comet may have been a primordial body of either the Solar System or that it may have originated from another planetary system.[23] The comet may have also originated from the Oort cloud.[19] A 1976 analysis of photometry and water loss rates estimated that the nucleus had a radius of around 2.1 km (1.3 mi) and an albedo of around 0.67.[7] A photometric analysis of Kohoutek, using Mercury as a reference, established an upper limit of 30 km (19 mi) for the diameter of Kohoutek's nucleus.[30] An attempt to detect a radar echo from Kohoutek's nucleus using the Haystack Radio Telescope received no radar returns, constraining the nucleus's size to under 250 km (160 mi).[31] The comet has a total absolute magnitude (at 1 AU) of 5.8 and a nuclear absolute magnitude of 9.5.[6] During Kohoutek's 1973–74 apparition, its tail's width ranged from around 30,000 km (19,000 mi) near the coma to 300,000 km (190,000 mi) farther away. Detection of positive carbon monoxide ions showed that the tail was at least 20 million km (12 million mi) in length.[32] A more yellow and orange appearance of the dust tail of Kohoutek during its perihelion – as observed by astronauts on Skylab – was likely the result of light scattering by basaltic dust particles with sizes of around 0.5 μm. The tail lacked color closer to the coma near perihelion, indicating a large distribution of particle sizes and resulting in a white appearance.[33] Observations from the Joint Observatory for Cometary Research in Socorro, New Mexico, were able to trace the blue ion tail of Kohoutek – featuring more prominently than the comet's dust tail – to a distance of 0.333 AU (49,800,000 km; 31,000,000 mi) away from the nucleus.[34] The particle density within the tail several million miles away from the nucleus was about 10 ions per cubic centimeter, while the maximum electron density within the tail was around 20,000 electrons per cubic centimeter.[32][35] At a distance of around 0.5 AU from the Sun, the plasma outflow in Kohoutek's tail generated a weak magnetic field with a strength comparable to the interplanetary magnetic field.[36]

 
Sequence of images of Kohotuek at perihelion taken via coronagraph

Analyses of Kohoutek have provided different assessments of the scale of the comet's release of dust and gas, with some suggesting that Kohoutek is relatively dust-rich (and consequently gas-poor) and others suggesting that the comet is relatively dust-poor (and consequently gas-rich).[37][14] Between 16 and 29 January 1974, the nucleus was expelling roughly 1,675 kg of gas and 16,000 kg of dust per second on average.[37][38] The predominance of dust was thought to have been demonstrated by the emergence of an antitail when the Earth passed through the plane of Kohoutek's orbit; antitails are composed of relatively large solid particles that disperse around the nucleus.[19] Particles in the antitail had radii larger than approximately 10 μm while particle radii in the coma and tail were less than 1 μm. At a distance of 0.23 AU from the Sun, the less reflective material in the coma had an effective temperature of 720 ± 20 K while the material in the antitail featured effective temperatures of 565 ± 10 K.[39] Intense solar heating near the time of perihelion greatly reduced the size of particles in the antitail, leaving behind only particles with initial sizes of at least 100–150 μm and leading to a decrease in the antitail's brightness following perihelion.[40] Silicates were also detected in the tail and antitail via infrared astronomy.[19][41][42] On 2 December 1973, Kohoutek was expelling about 900 billion dust molecules per second. However, Kohoutek became less dusty following perihelion, with dust production lowering to around 30 billion dust molecules per second on 31 January 1974.[41] This transition was also underscored by an increase in the gas-to-dust ratio of Kohoutek by at least a factor of 2 after perihelion.[43] The change may have been enabled by the evaporation of ice-covered surfaces as Kohoutek drew closer to the Sun.[7] The ejection of meteoroids during Kohoutek's approach and passage of the Sun added about 1 billion kg of mass to the zodiacal cloud.[28] Smaller micrometeoroids were detected by the HEOS 2 satellite when it crossed the orbital plane of the outgoing comet around 9 June 1974, with the micrometeoroids being detected over the course of around 60 days surrounding the plane traversal; these micrometeoroids had masses ranging between 10−13–10−11 g.[44][45]

 
Kohoutek as seen from Skylab in December 1973

Later photometric analyses indicated that Kohoutek was a gassy comet with a high gas-to-dust ratio emblematic of comets entering the inner Solar System for the first time, suggesting a nucleus rich in volatiles and relatively depleted in refractory substances.[37][46] Analyses of Kohoutek's coma and tail in the near-ultraviolet found the roughly equal presence of hydrogen atoms and hydroxide, suggesting that these chemical species were once constituents of water. At a distance of 1 AU from the Sun, Kohoutek was losing roughly 1 million tons (0.9 million tonnes) of water per day.[19] The mass of water lost between 60 days before perihelion to 60 days after perihelion, when Kohoutek would have been ejecting the most water, was approximately 64 billion kg.[7] The mass loss due to the ejection of water after perihelion was roughly two times less than before perihelion. The surface of Kohoutek's nucleus was likely covered in a mix of particles and water ice stored in clathrates. Much of this water was evaporated away as Kohoutek approached perihelion due to increased insolation, leaving behind only subsurface ices and smaller pockets of water on the nuclear surface.[7] The uneven outgassing behavior of both water and other volatiles indicates that Kohoutek's nucleus likely has a heterogeneous composition and structure on scales of around 10 m (33 ft). Jets of vaporizing volatiles likely emanated from exposed areas where less volatile ices previously vaporized.[47] Later analysis of spectrograms of Kohoutek provided strong evidence of the presence of the water cation (H
2O+
), particularly in the comet's tail.[48][49] This chemical species was most likely the result of the photoionization of neutral water (H
2O) very near the nucleus.[50][51]

Atomic oxygen and atomic carbon were also detected as the likely products of dissociating carbon monoxide or carbon dioxide from the nucleus.[52] The nucleus also outgassed hydrogen at rates of up to approximately 4.5 × 1029 atoms per second at speeds of around 7.8 ± 0.2 km/s.[53][54] Due to the low mass of hydrogen and the weak gravitational pull of Kohoutek, the cloud of hydrogen surrounding the comet was of great extent, extending over 30 million km (19 million mi) across;[53][55] the hydrogen cloud was thus larger than the disk of the Sun.[56] Within the cloud, the ratio of deuterium to atomic hydrogen was at most 1 percent.[54] The atomic hydrogen was later understood to be the product of the photodissociation of water ice present in Kohoutek's nucleus.[57] The nucleus may also have been once covered by a roughly meter-thick layer of highly volatile substances that quickly outgassed when Kohoutek first approached the inner Solar System.[22] Cyanide was first observed within Kohoutek's coma on 15 October 1973, while the comet was at a heliocentric distance of 1.8 AU.[14] The spectrographic signature of methyl cyanide at a wavelength of 2.7 mm was also detected in the nucleus of Kohoutek.[58] Radio and microwave observations of the comet identified hydrogen cyanide, methylidyne radicals, and ethyl alcohol in addition to hydroxide and water.[19][59][60] Other chemical species identified in the inner coma of Kohoutek included the amino radical, diatomic carbon, and sodium iodide.[61][62] Emission signatures of tricarbon and nitrogen gas were also detected.[62][63] Unlike in previously observed comets, the cyano radicals and diatomic carbon in Kohoutek's coma were not distributed spherically but instead elongated significantly away from the sun to distances of up to 10,000,000 km (6,200,000 mi).[62]

Observational history edit

 
Kohoutek as seen from the Kitt Peak National Observatory on 28 April 1973

Following Luboš Kohoutek's discovery of his eponymous comet, additional photographic observations taken on 30 March and 2 April 1973 showed that the comet's coma was highly condensed and 20 arcseconds in diameter. The comet was last observed by Kohoutek on 5 May 1973 before it became too faint and unremarkable to observe or discern against the glare of twilight.[11] At this stage, the comet's brightness was around magnitude 14.[64] After several months of poor visibility, the comet was detected by Japanese astronomer Tsutomu Seki on 23 September; the comet's apparent magnitude had brightened to magnitude 11 but it remained a diffuse object.[11] By the time the comet was recovered, it had neared to a distance of 2.2 AU away from the Sun.[15] While the comet previously appeared as only a faint, featureless nebulosity, by late September a tail had become conspicuous, appearing first in a broad and fan-like form extending 2 arcminutes to the north.[15] The coma grew to about 1 arcminute in diameter by mid-October 1973 as the comet brightened. By the end of the month, both the nucleus and a lengthening tail had become clearly apparent.[65]

In November 1973, Kohoutek became bright enough to be visible to the naked eye.[13] The ion component of the comet's tail was first noted on 21 November accompanying the brighter dust component.[15] The comet brightened to an apparent magnitude of 2.8 by 22 December 1973 before becoming indiscernible to ground-based observers due to Kohoutek's conjunction with the Sun;[13] between 24 and 31 December the comet was within 10° of the Sun.[11] During this period, the comet experienced a surge in brightness that – although not clearly observable from the Earth's surface – placed it in the echelon of great comets.[66] Kohoutek was at its brightest during this period, becoming a roughly –3rd magnitude object.[11] Kohoutek was a much brighter object in the infrared, reaching magnitudes of at least –4.75 and –5.70 at wavelengths of 10 microns and 20 microns, respectively.[62] At its closest approach, the comet was visually separated by only around 0.75° from the center of the Sun.[15] While the comet was too close to the Sun to be discernible from the ground, astronauts on Skylab and Soyuz 13 were able to observe the comet during its perihelion.[64] The astronauts on Skylab noted that the comet was distinctly yellow and estimated that Kohoutek at its brightest was comparable to the magnitude –1.6 brightness of Jupiter.[11] An antitail emerged during Kohoutek's close passage, stretching as far as 5–7° from the comet towards the Sun.[15] The separate gas and dust tails typically seen on comets were not observed from Skylab; instead, the comet uniformly took on a yellow texture, transitioning to white and later to a mottled violet appearance.[67] The strikingly yellow color of the comet at perihelion was due to the scattering of sunlight by sodium released by the comet.[68]

 
Illustration of Kohoutek on 29 December 1973 by Skylab 4's Edward Gibson
 
Progressive views of Comet Kohoutek as viewed by SL4 astronauts

I just finished taking the 233 photos and Kohoutek is not looking like our old, pretty, graceful-looking, blue-white comet any more. It's getting so close to the Sun now that the tail is fanning out; it's very short. I think I can't see the rest of the tail just because it's so light. But what I can see behind the comet now, the—the [coma] is getting quite large and bright, and the tail, all we can see is a fan behind it. And we're beginning to see some reds and some yellows in it.

— Gerald P. Carr, speaking to NASA Mission Control Center on 25 December 1973, Skylab Air-to-Ground Voice Transcription (Tape #MC1309/1)[69]

Kohoutek once again became observable to ground-based observers beginning on 27 December 1973. For ground observers, the comet was at most a 0th or 1st magnitude object.[11] By the time Kohoutek had reached a more favorable position for viewing by the general public, it had faded to around magnitude 2.[64] Although the comet was dimmer than anticipated, it was nonetheless among the ten brightest comets as seen from Earth between 1750 and 1994.[70] The comet rapidly dimmed following its perihelion on 28 December, diminishing to magnitude –1.5 on 1 January 1974 and reaching magnitude 4 by 10 January 1974. By the end of January 1974, Kohoutek was too faint to be seen with the unaided eye.[13] The comet dimmed to around 10th magnitude towards the end of March 1974, after which it became too faint to clearly detect against the backdrop of the zodiacal light.[11] Unlike on the comet's inbound trek, its appearance on the outbound trek was much more diffuse and nebulous.[71] When the comet returned to the same distance from the Sun at which it was discovered, it was over 100 times fainter than at its first detection.[22] The comet was last photographed in early November 1974 at a heliocentric distance of around 5 AU with an apparent magnitude of 22.[64] At its greatest visual extent, Kohoutek's tail was well-defined and spanned 25° in length.[13] In January 1974 its tail featured both a helical structure and a more irregular cloud-like structure about 0.1 AU away from the nucleus.[72] Kohoutek's antitail spanned as much as 3° for ground observers;[13] the antitail became more diffuse and dim following perihelion, making its visibility less favorable.[68] A faint meteor shower seen on 1–3 March 1974, concurrent with Earth's closest pass of Kohoutek's orbit, may have been directly associated with Kohoutek.[73]

Brightness predictions edit

 
The light curve of Kohoutek plotted from ground-based observations, with the perihelion denoted by the red line. While initial predictions assumed the comet's luminosity would scale to the 4th or even 6th power of its heliocentric distance, its brightness on approach scaled more closely with the second power.

Kohoutek's anticipated close passage of the Sun and its pristine condition – having likely never approached the Sun previously – made the comet a candidate for becoming one of the brightest comets of the 20th century. Conventional wisdom held that the brightness of a comet was scaled according to the inverse fourth power of its distance from the Sun, and it was customary at the time to use this assumption in predicting the peak brightnesses of newly discovered comets.[10] The value of the power (denoted n) would be repeatedly changed in subsequent estimates from the conventional value of 4, with estimates generally using values of n between 3–6.[74] Kohoutek's distance at the time of its discovery meant that its intrinsic brightness could increase by more than a million-fold using these assumptions.[19] While a more accurate estimate for the comet's ultimate apparent brightness – around magnitude –2.3 – could be derived from early observations,[12] some of the first extrapolations of the comet's brightness using the initial photographic observations predicted apparent magnitudes as bright as magnitude –10 near perihelion; such a remarkably bright comet would be visible in daylight. Estimates later reached as bright as magnitude –12, comparable to the brightness of the full Moon. The high peak luminosity also implied ample visibility: early projections showed Kohoutek reaching naked-eye visibility in early November and then becoming as bright as Jupiter by mid-December, with increasing brilliance in January 1974 following its perihelion. Kohoutek was billed by the press as the "Comet of the Century" when these estimates were publicized.[11][24][75][76] Fred Lawrence Whipple also remarked that the comet could "well be the comet of the century."[3]: 1  Brian Marsden stated that "an object [as large as Comet Kohoutek] should achieve unusual brightness and produce an exceptional tail" with twelve weeks of naked-eye visibility, but also cautioned that "some very promising comets of the past [have] fizzled out."[77][78] The Associated Press reported in early April 1973 that astronomers believed that the comet's approach "could be the most spectacular astrophysical event of the [20th] century".[77]

 
Kohoutek's brightness (observations plotted as points) fell short of predictions based on the light curves of past comets like Arend–Roland and Bennett (the solid and dashed lines, respectively).

Although the most bullish predictions caught the attention of the press and the general public, some astronomers – like S. W. Milbourn and Whipple – were more uncertain and held that such predictions were optimistic.[11][19] Regardless of its luminosity, the comet would be too close to the sun to be seen by ground observers at its brightest.[74] British Astronomical Association (BAA) circular 548, published on 25 July 1973, provided an alternative prediction of magnitude –3 for Kohoutek's peak brightness.[11] Higher-end projections of Kohoutek's peak brightness remained as high as magnitude –10 into August 1973. An article in Nature published in the final week of September 1973 suggested that Kohoutek's peak brightness could have a greater than 50 percent chance of being within two magnitudes of –4.[25] The National Newsletter accompanying the Journal of the Royal Astronomical Society of Canada in October 1973 estimated that Kohoutek would remain visible to the naked eye for four months bracketing perihelion.[79] Brightness predictions were revised downward following the comet's behavior as perihelion approached.[16] On 11 October 1973, BAA circular 549 provided a revised estimate of magnitude –4 for Kohoutek's brightest apparent magnitude. While still bright, such a brightness would yield only around ten days of clear naked-eye visibility for observers in the Northern Hemisphere.[11] Publicized predictions of the comet were scaled back in November 1973.[80] Although Kohoutek brightened by a factor of nearly a million by perehelion, sufficiently "to be a fine object for experienced observers when seen under ideal conditions in clear skies away from city lights" according to Whipple, its peak magnitude of –3 fell short of the most publicized projections and proved mediocre to the public eye;[19][22] however, the comet's ultimate brightness was close to the published lower-end predictions.[11] Whipple later quipped that "if you want to have a safe gamble, bet on a horse – not a comet."[81]

Despite higher assumed values of n, the light curve of Kohoutek from 24 November 1973 to perihelion best fit n = 2.2 while its light curve after perihelion to 16 January 1974 best fit n = 3.3 or n = 3.8.[82] The more optimistic use of n = 6 led to overestimates of Kohoutek's perihelion brightness by as much as a factor of 2800.[83] The early brightness of Kohoutek around the time of its discovery may have been influenced by the intense outgassing of highly volatile substances; such volatiles may have been abundant in the nucleus if Kohoutek had never previously entered the inner Solar System.[75][84] The degree of outgassing may have been enhanced by extremely porous outer layers of the nucleus that readily allowed the most volatile ices to vaporize at great distances from the Sun.[85] In this model, the comet would have brightened quickly in the early stages of its solar approach, at about n = 5.78, before brightening more in line with shorter period comets.[66][22] The early burst would have led to inflated expectations for the comet's ultimate brightness.[76] A separate study of long-period comets published in 1995 found that comets with initial semi-major axes greater than 10,000 AU brighten more slowly and less substantially before perihelion than shorter period comets.[10] Such comets are discovered at farther distances from the Sun than other comets as a result.[86] It is now understood that Kohoutek's light curve preceding its 1973 perihelion was typical for comets with similar orbits.[10]

Observing campaigns and scientific results edit

 
Artist's concept of Skylab 4 astronauts observing Comet Kohoutek via the space station's airlock

Kohoutek was the subject of intense scientific investigation and was observed over an unprecedentedly large range of the electromagnetic spectrum.[14] Kohoutek represented the first time radio astronomy techniques were used to study a comet.[19] The possibility that the comet could be entering the inner Solar System for the first time since its formation – making it potentially illustrative of the evolution of comets and conditions in the early Solar System – made it an attractive scientific target.[18]: 12  The comet's exceptionally early detection, as well as the concurrence of its perihelion with Skylab 4, allowed for and motivated the coordination of Operation Kohoutek, a cometary observing campaign backed by NASA and involving a wide array of instruments and observation platforms. The resulting study of Kohoutek was in its time the most comprehensive and detailed of any comet; the scale of the international effort to observe the comet would not be surpassed until the 1986 International Halley Watch for Halley's Comet.[23][75]

 
The crew of Skylab 4 discussing their observations of the comet via television on 28 December 1973
 
Skylab 4 emblem

Of particular interest were the molecular makeup of the comet and the dust in its tail.[68] Many of the observations focused on the possible detection of water, which until Kohoutek had been never detected in a comet.[23][87][e] While the presence of water in comets could be inferred by the identification of hydroxide and hydrogen constituents in previous comets, the prominent spectral signature of water in Kohoutek's tail was the first conclusive evidence that comets contained water.[89] Observations also aimed to detect complex molecules in the comet; before Kohoutek, no molecule with more than three atoms had ever been detected in a comet.[90] The detection of methyl cyanide in Kohoutek's nucleus was the first time such a molecule had been observed in a comet. It was also the first direct evidence of the hypothesis that comet nuclei harbored complex and stable chemical compounds (also known as "parent molecules") that sublimated or dissociated into the chemically unstable radicals and simpler molecules often identified in cometary spectra.[58][50] Kohoutek also marked the first time that hydrogen cyanide was identified in a comet,[88] supporting the hypothesis that hydrogen cyanide could be a parent molecule of the cyano radical previously detected in comets.[91] The signature of silicon in infrared spectra of Kohoutek offered the first direct evidence of silicon in comets.[11] The identification of a hydrogen cloud surrounding Kohoutek and its Lyman-alpha line signature validated earlier predictions that comets amass hydrogen. The low abundance of methane in Kohoutek and what Whipple described as "chemically ill-mated carbon molecules" suggested that comets were formed from the aggregation of compounds at low temperatures as opposed to the cooling of hot gasses, possibly pointing to a larger role of the interstellar medium in providing the constituents of cometary compositions.[88] Acetone, ammonia, and helium were not detected in Kohoutek despite searches.[60]

 
In observing Kohoutek, Mariner 10 became the first interplanetary spacecraft to observe a comet.

Skylab, the Orbiting Astronomical Observatory, the Orbiting Solar Observatory, ground observatories, and various sounding rockets were among the many observing platforms used to investigate Kohoutek during the comet's approach.[90] Some resources in other projects under the auspices of NASA were redirected to study the comet. The newly built Joint Observatory for Cometary Research near Socorro, New Mexico, was made operational in time to observe the comet.[16][92] In June 1973, NASA also briefly considered launching a spacecraft to intercept and investigate the comet via either a Thor-Delta or Atlas-Centaur launch vehicle but scrapped the proposal due to insufficient preparation time.[93][94] Skylab 4 – the third crewed mission to the Skylab space station – was scheduled favorably for the passage and perihelion of Kohoutek.[90] As a result, a substantial observation program targeting Kohoutek was appended to the original Skylab 4 mission, with the launch date selected due to scientific interest in the comet.[95][18]: 12  The observation of the comet from Skylab was primarily conducted using instruments already on the space station, along with the backup of the Far Ultraviolet Camera/Spectrograph from Apollo 16. Due to Skylab's orbit around Earth, the comet could only be observed for at most 26 minutes at a time. When Kohoutek appeared closest to the Sun on 27 December 1973, Skylab instruments were trained on the comet almost continuously for 21 consecutive orbits.[96] Mariner 10, en route to Venus, also made ultraviolet measurements of Kohoutek at a distance of around 0.7 AU in January 1974,[55][97] making the comet the first to be observed by an interplanetary spacecraft.[64] Although the comet's unexpected faintness prevented clear television images from being obtained by the spacecraft, Mariner 10's ultraviolet spectrometer nonetheless collected useful data concerning Kohoutek's hydrogen coma.[98] Pioneer 6 and Pioneer 8 recorded data from within the comet's tail in 1974.[99]

The results of the observations conducted as part of Operation Kohoutek were presented in June 1974 at a workshop held at the Marshall Space Flight Center.[100] Comet science saw considerable advances as a result of the observational research conducted on Kohoutek,[75] ushering in what Fred Whipple termed a "'renaissance' of cometary research".[22] At the time, most scientists accepted Whipple's hypothesis that cometary nuclei were "dirty snowballs" made mostly of ices. However, there were other alternative models for comet nuclei, such as the "sand bank" model championed by British astronomer Raymond A. Lyttleton which considered nuclei as loose collections of dust particles with negligible amounts of ice.[101][3]: 5  The detection and identification of various gasses emanating from Kohoutek validated the predictions of Whipple's model.[89][102][103] Kohoutek's behavior led to the development of more detailed models seeking to explain the physical structure of comet nuclei.[47] One proposal suggested that Kohoutek belonged to a subset of comets containing a non-volatile dust mantle around an icy volatile core.[104] The occultation of the radio source PKS 2025–15 by Kohoutek's tail on 5 January 1974 also served as an opportunity to study interplanetary scintillation.[105][106]

Media coverage and viewing events edit

 
Luboš Kohoutek briefing the press on expectations for the comet on 5 January 1974

A hundred years from now, how will our great, great grandchildren remember 1973?
In a future age, when the names of Nixon and Brezhnev are dimly remembered, and those of Ervin and Mitchell and Dean are minor footnotes in scholarly treatises, the name and the discovery that will illuminate the 1973 will be Lubos Kohoutek.

— William Safire, "Kohoutek's Comet", The New York Times (30 July 1973)[107]

Kohoutek was in its time the most publicized comet aside from Halley's Comet.[15] The media attention was brought about by a combination of factors, including the early predictions of its brightness, its passage concurrent with the Christmas and holiday season, the involvement of many observatories and powerful telescopes, and the possible effort of a manned spaceflight mission – Skylab 4 – to investigate the comet.[16][108] NASA also pursued an extensive public relations campaign that led to widespread coverage of the comet's approach in American newspapers in the final six months of 1973.[16] Dale D. Myers, the Associate Administrator for Manned Space Flight at NASA, commented in July 1973 that "comets [of Kohoutek's] size come this close once in a century," further adding to the public interest.[16][13] On the 30 July 1973 edition of the New York Times, columnist William Safire wrote that Kohoutek "may well be the biggest, brightest, most spectacular astral display that living man has ever seen".[107] In August 1973, a reporter from The Mercury News in San Jose, California, wrote that researchers preparing to study the comet at NASA's Ames Research Center were calling Kohoutek "the comet of the century"; this honorific quickly became associated with the comet. NASA's decision to postpone the launch of Skylab 4 to support observations of the comet only further intensified public interest and added to the attention of the press towards Kohoutek after 16 August 1973. Despite more reserved and cautious statements from scientists regarding the comet's luminosity, stories referencing the more bullish and earlier estimates of Kohoutek's brightness continued to circulate as the comet drew closer, disregarding revised estimates.[16] One edition of Time placed the comet on its cover.[13] However, NASA spokespeople continued to relay an expectation that the comet would be a generational event. As November 1973 passed, newspapers began to more frequently convey the guarded skepticism that surrounded Kohoutek's brightness. Seizing the opportunity created by the comet in giving NASA good publicity, an adviser to NASA administrator James C. Fletcher proposed a half-hour television special featuring the comet, Skylab, and a Christmas message from the first family of the U.S. However, John Donnelly, the NASA Assistant Administrator for Public Affairs, derided the proposal because of its intertwining of politics with NASA. The proposal continued to be hotly contested within NASA but was eventually dropped. Although a spokesman for the Goddard Space Flight Center later stated that Kohoutek was a "roaring success" for science, "from a public relations point of view, it [was] a disaster."[16]

 
The Queen Elizabeth 2 (pictured in August 1973) sailed on a special three day cruise offering telescope views and comet lectures in December 1973

Queen Elizabeth 2 sailed on a sold-out "cruise to nowhere" dedicated to the comet from 9–12 December 1973, including guest of honor Luboš Kohoutek; Isaac Asimov and Kenneth Franklin were also present on the cruise.[109][110] Astrophotography discussions and lectures discussing astronomy and the comet, led by scientists from Dowling College, were also held on board.[110][111] Overcast and rainy conditions prevented views of the comet during the trek, which departed from New York and remained along the U.S. East Coast before returning to New York.[109][112][113] In his final autobiography, Asimov later wrote that "even if it hadn't been [cloudy and rainy every night], Comet Kohoutek proved a colossal disappointment."[114] Queen Elizabeth 2 later embarked on similar cruises in the Caribbean in January 1974 which afforded better views of the comet; Buzz Aldrin, Hugh Downs, Burl Ives, and Carl Sagan featured on the Caribbean cruises, with Hayden Planetarium director Mark Chartrand serving as the cruise's resident astronomer.[109][113] The SS Rotterdam departed on a nine-day cruise beginning on 3 January 1974 to Puerto Rico and the Virgin Islands that was billed as a "Caribbean Comet Watch Cruise"; educational astronomy segments on the cruise were led by astronomer Lloyd Motz. Freelandia flew 149 of its members to Peru to view the comet in December 1973. Another chartered trip sponsored by the Hayden Planetarium to take passengers to observatories to view the comet was canceled.[113] The American Automobile Association advised travelers to bring binoculars on roadtrips between December 1973 and February 1974 in anticipation of the comet's apparition.[115] Planetariums throughout the U.S. launched comet-centered events and established hotlines offering information regarding Kohoutek.[16] The William Miller Sperry Observatory at Union County College and the observatory on the roof of Boyden Hall at Rutgers University–Newark – both in New Jersey – made their facilities accessible to the public interested in the comet, with the former maintaining a phone line for updates on the comet.[116]

Cultural impact edit

 
Kohoutek's anticipated brightness and apparition around Christmas was a spiritual significance in some religious fundamentalist circles.

It is among nonpatients that I have seen the most interest in the comet; in some instances the impact has already been profound. Many Christians have seen an umistakable link between the fact of Kohoutek's December 28 perihelion [...] and the Christmas observance. Some individuals have seemed to downplay the signifiance the event has for reasons of propriety or in the interest of appearing sensible. [...] A fair number of young adults have taken the comet to be some kind of sign, the significance to each individual varying with his specific religious or general spiritual outlook.

— Lawrence Weiner, letter to the editor, American Journal of Psychiatry (March 1974)[117]

With predictions of Kohoutek's exceptional brightness being well-circulated, the comet became a cultural and media phenomenon by mid-summer 1973, leading to widespread cometary paraphernalia, apparel, and accessories.[76] Sales of telescopes rose sharply leading up to the comet's anticipated appearance. Edmund Scientific Corporation reported a 200 percent increase in its sale of telescopes in 1973 relative to 1972.[3]: 2  Sales for telescopes and binoculars quadrupled at Macy's after the company ran a seven-column ad in the New York Times. Interest in popular astronomy books also increased as the comet neared. Pinnacle Books published and quickly sold 750,000 copies of astrologer Joseph Goodavage's book "The Comet Kohoutek", which described the comet as a "harbinger of God".[113][118] Astronomers appeared more frequently on television talk shows and were in greater demand as lecturers to speak on comets;[113] Carl Sagan appeared on The Tonight Show Starring Johnny Carson to discuss the comet.[119]: 6 

The timing of Kohoutek's visible apparition around Christmastide was of spiritual significance to fundamentalist Christians; in some circles, Kohoutek became known as the "Christmas comet". It renewed interest in the nature of the Star of Bethlehem, including the idea that the event may have been a comet. Some fundamentalist Protestants interpreted the comet as a harbinger of the Second Coming. Radio preacher Carl McIntire stated that the comet was "so beyond anything men have ever seen before" and that "only the Holy Scripture [offered] anything to explain it."[120] Kohoutek also took on spiritual significance in the New Age movement and other followers of Western esotericism.[13] One view was that the comet heralded a new cosmic age – the "age of Kohoutek". Proponents of this view organized the Kohoutek Celebration of Consciousness at the Bill Graham Civic Auditorium in San Francisco in January 1974.[121] For some, the comet's arrival was a portent of disaster.[122] In 1973, David Berg, founder of the Children of God, predicted that Comet Kohoutek foretold a colossal doomsday event in the United States by the end of January 1974 because of divine judgment and "America's wickedness". Some of the movement's followers intended to leave the U.S. in response to the impending comet.[120] There were other circulated fringe claims predicting that the comet would cause mass hysteria or spell death for humanity by igniting the global oil supply.[3]: 2 

Because Kohoutek fell far short of expectations, its name became synonymous with spectacular disappointment.[123][124]: 199  Russell Baker described the comet as "the biggest flopperoo since 'Kelly' hit Broadway" and "the Edsel of the firmament", among other witty metaphors.[125] While newspapers had been touting the comet's brightness for the latter half of 1973, the anticlimactic display led to satirical and parodical reporting following Kohoutek's passage. For instance, the Chicago Tribune featured a satirical article linking the optimistic brightness predictions to an effort to distract the public from the Watergate scandal or to a conspiracy to boost telescope sales.[16] The widely circulated inaccurate projections came during a time of increasing distrust of the sciences that Time termed a "deepening disillusionment".[126] Mainstream media shied away from extensive coverage of comets following Kohoutek; despite Comet West becoming bright enough to be visible in daylight in March 1976, West received little attention from the press compared to the media frenzy that preceded Kohoutek.[76] Though astronomers and the sciences received backlash due to the comet's underwhelming performance, much of the general public's disdain was also directed towards astrologers and cultists who ascribed a transcendental significance to the comet's apparition.[118]

In response to the disappointing display from the comet, students at Pitzer College organized the Kohoutek Music and Arts Festival in January 1974,[127] which became an annual event featuring various musical artists.[128] Several music albums and songs released in the 1970s and 1980s were dedicated to or named after Kohoutek, such as "Kohoutek" from Journey's eponymous debut album (released in 1975).[129][130] Sun Ra played a concert at The Town Hall in New York dedicated to Kohoutek's arrival on 22 December 1973.[131] Other musical groups with works influenced by the comet included Kraftwerk, Pink Floyd, Argent, R.E.M., and Weather Report Girl.[119]: 7  References to Kohoutek permeated other forms of popular media, such as in the comic strip Peanuts over a week-long period,[119]: 7  in the sitcom El Chavo del Ocho, and a poem by Jaime Sabines.[132]

In The Defenders #15 (September 1974), the Comet Kohoutek is mentioned as having freed Magneto from imprisonment within the Earth's core.[133]

See also edit

Notes edit

  1. ^ A teaching guide published by the Educational Programs Branch of the NASA Goddard Space Flight Center lists the pronunciation of Kohoutek as "KŌ-HÜ'-TEK".[1]: iii  A January 1974 article in the New York Times provided the phonetic pronunciation "ko-ho-tek" without any accented syllables.[2] A special report on the comet in Time gave the phonetic pronunciation "ko-hoe-tek".[3]: 1 
  2. ^ Most comets have an albedo of around 0.04.
  3. ^ The designation C/1973 E1 reflects the modern comet designation scheme adopted by the International Astronomical Union in 1995, and indicates that Comet Kohoutek appeared once and was the first comet discovered in the first half of March 1973. However, during the time of perihelion the comet was contemporaneously designated as 1973f as it was sixth comet discovered in 1973, or alternatively as 1973 XII as the comet was the twelfth to reach perihelion in 1973.[9][10][1]: 3 
  4. ^ All mentions of apparent magnitude in this article refer to brightness in visible light unless otherwise noted.
  5. ^ a b Observations identified the cation of water (H
    2    O+
    ) in Kohoutek. It would not be until Comet Bradfield (1974 III) that neutral water (H
    2    O    ) was detected in a comet.[88]
  6. ^ 1971 UG is a main-belt asteroid about 10 km in diameter discovered by Kohoutek on 26 October 1971.[20] It is also known as 1980 RT3 and 1995 UZ44. It has been observed every year since 1998.
  7. ^ The first comet discovered by Kohoutek in 1973 was designated 1973e (modern designation: C/1973 D1) and has an orbital period of about 36,751 years. It reached its perihelion on 7 June 1973 and was last observed in October 1973.[21][15]

References edit

  1. ^ a b c d e Chapman, Robert D. (September 1973). Comet Kohoutek: A Teacher's Guide With Student Activities (PDF) (Technical Memorandum). Greenbelt, Maryland: NASA. (PDF) from the original on 6 July 2022. Retrieved 6 July 2022.
  2. ^ McElheny, Victor (7 January 1974). "Discoverer of Comet: Lubas Kohoutek". The New York Times. New York. p. 61. from the original on 6 July 2022. Retrieved 6 July 2022.
  3. ^ a b c d e "SPECIAL REPORT: Kohoutek: Comet of the Century". Time. Vol. 102, no. 25. 17 December 1973. from the original on 8 July 2022. Retrieved 8 July 2022.
  4. ^ a b c d e f g "JPL Horizons Orbital Elements at epoch 1600 and 2500". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. from the original on 3 August 2022. Retrieved 3 August 2022. Solution using the Solar System Barycenter. Ephemeris Type: Elements and Center: @0 (To be outside planetary region, inbound epoch 1600 and outbound epoch 2500. Aphelia/orbital periods defined while in the planetary-region are misleading for knowing the long-term inbound/outbound solutions.)
  5. ^ a b c d "C/1973 E1 (Kohoutek)". Minor Planet Center. from the original on 20 September 2022. Retrieved 7 July 2022.
  6. ^ a b c d "C/1973 E1 (Kohoutek)". Small-Body Database Lookup. Jet Propulsion Laboratory. from the original on 7 February 2022. Retrieved 7 July 2022.
  7. ^ a b c d e f g O'Dell, C. R. (June 1976). "Physical processes in Comet Kohoutek". Publications of the Astronomical Society of the Pacific. 88 (523): 342–348. Bibcode:1976PASP...88..342O. doi:10.1086/129954. JSTOR 40675895. S2CID 120855634.
  8. ^ "Brightest comets seen since 1935". International Comet Quarterly. from the original on 18 September 2013. Retrieved 8 July 2022.
  9. ^ "Comet Names and Designations; Comet Naming and Nomenclature; Names of Comets". International Comet Quarterly. Archived from the original on 29 July 2012. Retrieved 7 July 2022.
  10. ^ a b c d Green, Daniel W E; Marsden, Brian G; Morris, Charles S (February 2001). "Brightness predictions for comets". Astronomy and Geophysics. 42 (1): 1.11–1.12. Bibcode:2001A&G....42a..11G. doi:10.1046/j.1468-4004.2001.0420011.11.x. S2CID 12022471.
  11. ^ a b c d e f g h i j k l m n o p Hendrie, Michael J. (February 2000). "Comet Kohoutek 1973f". Journal of the British Astronomical Association. 110: 9–19. Bibcode:2000JBAA..110....9H.
  12. ^ a b c d e f Kohoutek, Luboš (December 1974). "On the discovery of Comet Kohoutek (1973f)". Icarus. 23 (4): 491–492. Bibcode:1974Icar...23..491K. doi:10.1016/0019-1035(74)90011-6. S2CID 120800003.
  13. ^ a b c d e f g h i j k Stoyan, Ronald (2015). "Comet Kohoutek 1973/74". Atlas of Great Comets (English ed.). Cambridge, United Kingdom: Cambridge University Press. pp. 166–169. ISBN 9781316195727. from the original on 20 September 2022. Retrieved 6 July 2022 – via Google Books.
  14. ^ a b c d e f Biermann, L. (December 1973). "Comet Kohoutek". Nature. 246 (5433): 400–402. Bibcode:1973Natur.246..400B. doi:10.1038/246400a0. S2CID 42320124.
  15. ^ a b c d e f g h i j Marsden, Brian G. (December 1974). "Comets in 1973". Quarterly Journal of the Royal Astronomical Society. 15: 433–460. Bibcode:1974QJRAS..15..433M.
  16. ^ a b c d e f g h i j Benson, Charles Dunlap; Compton, William David. "Appendix F: Comet Kohoutek". Living and Working in Space: A History of Skylab. Washington, D.C.: NASA. from the original on 28 August 2021. Retrieved 14 July 2022.
  17. ^ Roemer, Elizabeth (1976). "Luminosity and Astrometry of Comets: A Review" (PDF). The Study of Comets, Part 1. 393. NASA: 380–409. Bibcode:1976NASSP.393..380R. (PDF) from the original on 26 May 2022. Retrieved 9 July 2022.
  18. ^ a b c MSFC Skylab Kohoutek Project Report (PDF) (NASA Technical Memorandum). Huntsville, Alabama: NASA Marshall Space Flight Center. October 1974. NASA TM X-64880. (PDF) from the original on 20 September 2022. Retrieved 8 July 2022.
  19. ^ a b c d e f g h i j Whipple, Fred L. (5 February 1976). "Comet Kohoutek in Retrospect". Proceedings of the American Philosophical Society. 120 (1): 1–6. Bibcode:1976PAPhS.120....1W. JSTOR 986346. S2CID 236815067.
  20. ^ "MPC object 8606". from the original on 4 March 2016. Retrieved 5 August 2022.
  21. ^ "C/1973 D1 (Kohoutek)". Small-Body Database Lookup. Jet Propulsion Laboratory. from the original on 7 February 2022. Retrieved 4 September 2022.
  22. ^ a b c d e f Whipple, F. L. (June 1989). "Comets in the space age". The Astrophysical Journal. 341: 1–13. Bibcode:1989ApJ...341....1W. doi:10.1086/167466. S2CID 121228906.
  23. ^ a b c d Dubin, Maurice (1975). "Foreword". In Gary, Gilmer (ed.). Comet Kohoutek: A Workshop Held at Marshall Space Flight Center. Vol. 355. Washington, D.C.: NASA. Bibcode:1975NASSP.355.....G. {{cite book}}: |journal= ignored (help)
  24. ^ a b "The Christmas Comet Begins Yielding Data". Science News. 104 (17): 262. 27 October 1973. doi:10.2307/3958219. JSTOR 3958219.
  25. ^ a b Lyttleton, R. A. (September 1973). "Prospects for Comet Kohoutek (1973f)". Nature. 245 (5422): 200–201. Bibcode:1973Natur.245..200L. doi:10.1038/245200a0. S2CID 4255566.
  26. ^ Stokley, James (22 December 1973). "Kohoutek Comet Now Visible". Science News. 104 (25/26): 400. doi:10.2307/3958267. JSTOR 3958267. S2CID 86901151.
  27. ^ Horizons output. "Osculating Orbital Elements for Comet C/1973 E1 (Kohoutek)".
  28. ^ a b Fulle, M (July 1988). "Meteoroids from comet Kohoutek 1973 XII". Astronomy and Astrophysics. 201 (1): 161–168. Bibcode:1988A&A...201..161F. S2CID 116263177.
  29. ^ a b "Horizons Batch for Heliocentric distance for 2022-2030". JPL Horizons. from the original on 4 August 2022. Retrieved 3 August 2022.
  30. ^ Ney, Edward P. (December 1974). "Multiband photometry of Comets Kohoutek, Bennett, Bradfield, and Encke". Icarus. 23 (4): 551–560. Bibcode:1974Icar...23..551N. doi:10.1016/0019-1035(74)90018-9. S2CID 121046622.
  31. ^ Chaisson, E.J.; Ingalls, R.P.; Rogers, A.E.E.; Shapiro, I.I. (February 1975). "Upper limit on the radar cross section of the comet Kohoutek". Icarus. 24 (2): 188–189. Bibcode:1975Icar...24..188C. doi:10.1016/0019-1035(75)90096-2. S2CID 119908758.
  32. ^ a b Jockers, K (December 1985). "The ion tail of Comet Kohoutek 1973 XII during 17 days of solar wind gusts". Astronomy and Astrophysics Supplement Series. 62 (4): 791–838. Bibcode:1985A&AS...62..791J. S2CID 120216058.
  33. ^ Jambor, B. J. (1975). "Dynamical and Colorimetric Study of the Dust Tail of Comet Kohoutek". In Gary, Gilmer (ed.). Comet Kohoutek: A Workshop Held at Marshall Space Flight Center. Vol. 355. Washington, D.C.: NASA. pp. 209–216. Bibcode:1975NASSP.355..209J. {{cite book}}: |journal= ignored (help)
  34. ^ Brandt, John C. (1975). "Large-Scale Observations of the Ion Tail from the Joint Observatory for Cometary Research". In Gary, Gilmer (ed.). Comet Kohoutek: A Workshop Held at Marshall Space Flight Center. Vol. 355. Washington, D.C.: NASA. pp. 15–18. Bibcode:1975NASSP.355...15B. {{cite book}}: |journal= ignored (help)
  35. ^ Wright, C.S.; Nelson, G.J. (April 1979). "Comet plasma densities deduced from refraction of occulted radio sources". Icarus. 38 (1): 123–135. Bibcode:1979Icar...38..123W. doi:10.1016/0019-1035(79)90092-7. S2CID 122229848.
  36. ^ Ershkovich, A.I. (March 1976). "Solar wind interaction with the tail of Comet Kohoutek". Planetary and Space Science. 24 (3): 287–291. Bibcode:1976P&SS...24..287E. doi:10.1016/0032-0633(76)90025-8. S2CID 121782993.
  37. ^ a b c de Almeida, A.A. (April 1996). "Photoelectric photometry of comet Kohoutek (1973 XII = C/1973 E1): the production rates of CN, C2, and solid refractory particles typical of dynamically new comets". Planetary and Space Science. 44 (4): 295–304. Bibcode:1996P&SS...44..295D. doi:10.1016/0032-0633(95)00130-1. S2CID 123609347.
  38. ^ Lisse, C. M.; A'Hearn, M. F.; Hauser, M. G.; Kelsall, T.; Lien, D. J.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F. (April 1998). "Infrared Observations of Comets by COBE". The Astrophysical Journal. 496 (2): 971–991. Bibcode:1998ApJ...496..971L. doi:10.1086/305397. S2CID 119698136.
  39. ^ Ney, Edward P. (May 1974). "Infrared Observations of Comet Kohoutek Near Perihelion". The Astrophysical Journal. 189: L141–L142. Bibcode:1974ApJ...189L.141N. doi:10.1086/181486. S2CID 120737009.
  40. ^ Sekanina, Zdenek; Miller, Freeman D. (January 1976). "On the nature of the anti-tail of Comet Kohoutek (1973f). II. Comparison of the working model with ground-based photographic observations". Icarus. 27 (1): 135–146. Bibcode:1976Icar...27..135S. doi:10.1016/0019-1035(76)90190-1. hdl:2027.42/21881. S2CID 56252570.
  41. ^ a b A'Hearn, Michael F.; Cowan, J. J. (October 1975). "Molecular production rates in Comet Kohoutek". The Astronomical Journal. 80: 852. Bibcode:1975AJ.....80..852A. doi:10.1086/111821. S2CID 121989799.
  42. ^ Gatley, I.; Becklin, E.E.; Neugebauer, G.; Werner, M.W. (December 1974). "Infrared observations of Comet Kohoutek (1973f)". Icarus. 23 (4): 561–565. Bibcode:1974Icar...23..561G. doi:10.1016/0019-1035(74)90019-0. S2CID 121839693.
  43. ^ A'Hearn, Michael F. (October 1975). "Spectrophotometry of comet Kohoutek (1973f = 1973 XII)". Astronomical Journal. 80 (10): 861–875. Bibcode:1975AJ.....80..861A. doi:10.1086/111822. S2CID 123614672.
  44. ^ Hoffmann, H.-J.; Fechtig, H; Grün, E; Kissel, J (1976). "Particles from Comet Kohoutek Detected by the Micrometeoroid Experiment on HEOS 2". International Astronomical Union Colloquium. 25 (2): 949–961. Bibcode:1976NASSP.393..949H. doi:10.1017/S0252921100034357. hdl:2060/19760014003. S2CID 118057535.
  45. ^ Grün, E.; Kissel, J.; Hoffmann, H. -J. (1976). "Dust emission from Comet Kohoutek (1973f) at large distances from the sun". Interplanetary Dust and Zodiacal Light. Lecture Notes in Physics. Vol. 48. pp. 334–338. Bibcode:1976LNP....48..334G. doi:10.1007/3-540-07615-8_503. ISBN 978-3-540-07615-5. S2CID 118694750.
  46. ^ Rieke, G. H.; Lee, T. A. (April 1974). "Photometry of Comet Kohoutek (1973f)". Nature. 248 (5451): 737–740. Bibcode:1974Natur.248..737R. doi:10.1038/248737a0. S2CID 4281170.
  47. ^ a b Huebner, W. F. (1975). "On the structure of the nucleus of comet Kohoutek (1973f)". In Gary, Gilmer (ed.). Comet Kohoutek: A Workshop Held at Marshall Space Flight Center. Vol. 355. Washington, D.C.: NASA. pp. 145–152. Bibcode:1975NASSP.355...15B. {{cite book}}: |journal= ignored (help)
  48. ^ Herzberg, G; Lew, H (February 1974). "Tentative Identification of the H
    2    O+
     Ion in Comet Kohoutek". Astronomy and Astrophysics. 31: 123–124. Bibcode:1974A&A....31..123H. doi:10.1017/S0252921100500864. S2CID 125675140.
  49. ^ Wehinger, Peter; Wyckoff, Susan (1976). "H20+ Ions in Comets: Comet Kohoutek (1973f) and Comet Bradfield (1974b)". International Astronomical Union Colloquium. 25 (Part1): 199–205. doi:10.1017/S0252921100500864.
  50. ^ a b Mendis, D. A.; Ip, W-H. (June 1974). "Behaviour of Comet Kohoutek (1973f)". Nature. 249 (5457): 536–537. Bibcode:1974Natur.249..536M. doi:10.1038/249536a0. S2CID 4297924.
  51. ^ Herbig, George (1975). "Spectroscopy of the Coma and Tail". In Gary, Gilmer (ed.). Comet Kohoutek: A Workshop Held at Marshall Space Flight Center. Washington, D.C.: NASA. pp. 233–235.
  52. ^ Feldman, Paul D.; Takacs, Peter Z.; Fastie, William G.; Donn, Bertram (23 August 1974). "Rocket Ultraviolet Spectrophotometry of Comet Kohoutek (1973f)". Science. 185 (4152): 705–707. Bibcode:1974Sci...185..705F. doi:10.1126/science.185.4152.705. JSTOR 1738738. PMID 17736378. S2CID 43534328.
  53. ^ a b Opal, C. B.; Carruthers, G. R.; Prinz, D. K.; Meier, R. R. (23 August 1974). "Comet Kohoutek: Ultraviolet Images and Spectrograms". Science. 185 (4152): 702–705. Bibcode:1974Sci...185..702O. doi:10.1126/science.185.4152.702. JSTOR 1738737. PMID 17736377. S2CID 45497893.
  54. ^ a b Huppler, D.; Reynolds, R. J.; Roesler, F. L.; Scherb, F.; Trauger, J. (November 1975). "Observations of comet Kohoutek /1973f/ with a ground-based Fabry-Perot spectrometer". The Astrophysical Journal. 202: 276–282. Bibcode:1975ApJ...202..276H. doi:10.1086/153974. S2CID 120798083.
  55. ^ a b Kumar, S.; Holberg, J.; Broadfoot, A. L.; Belton, M. J. S. (September 1979). "The Lyman-alpha observations of comet Kohoutek from Mariner 10". The Astrophysical Journal. 232: 616. Bibcode:1979ApJ...232..616K. doi:10.1086/157320. S2CID 120955159.
  56. ^ Marsden, Brian G. (1979). "Comet Halley and history". NASA Goddard Space Flight Center Space Missions to Comets. 2089: 179–196. Bibcode:1979NASCP2089..179M.
  57. ^ Feldman, Paul D. (28 January 1983). "Ultraviolet Spectroscopy and the Composition of Cometary Ice". Science. 219 (4583): 347–354. Bibcode:1983Sci...219..347F. doi:10.1126/science.219.4583.347. JSTOR 1689912. PMID 17815301. S2CID 37048944.
  58. ^ a b Ulich, B. L.; Conklin, E. K. (March 1974). "Detection of methyl cyanide in Comet Kohoutek". Nature. 248 (5444): 121–122. Bibcode:1974Natur.248..121U. doi:10.1038/248121a0. S2CID 4287565.
  59. ^ Huebner, W.F.; Snyder, L.E.; Buhl, D. (December 1974). "HCN radio emission from Comet Kohoutek (1973f)". Icarus. 23 (4): 580–584. Bibcode:1974Icar...23..580H. doi:10.1016/0019-1035(74)90023-2. S2CID 123086883.
  60. ^ a b Whipple, Fred L. (1977). "Comets: Data, problems, and objectives" (PDF). The Soviet-American Conference on Cosmochemistry of the Moon and Planets. 370: 923–929. Bibcode:1977NASSP.370..923W. (PDF) from the original on 10 July 2022. Retrieved 10 July 2022.
  61. ^ Delsemme, A. H.; Combi, M. R. (August 1983). "Neutral cometary atmospheres. IV - Brightness profiles in the inner coma of comet Kohoutek 1973 XII". The Astrophysical Journal. 271: 388–397. Bibcode:1983ApJ...271..388D. doi:10.1086/161204. S2CID 120962101.
  62. ^ a b c d Goraya, P. S.; Rautela, B. S.; Sanwal, B. B. (January 1986). "Absolute spectrophotometry of Comet kohoutek 1973f during post-perihelion passage". Earth, Moon, and Planets. 34 (1): 77–91. Bibcode:1986EM&P...34...77G. doi:10.1007/BF00054037. S2CID 120188816.
  63. ^ Wyckoff, S.; Wehinger, P. A. (March 1976). "Molecular ions in comet tails". The Astrophysical Journal. 204: 604. Bibcode:1976ApJ...204..604W. doi:10.1086/154209. S2CID 120955304.
  64. ^ a b c d e Hale, Alan (27 December 2020). "Comet of the Week: Kohoutek 1973f". RocketSTEM. from the original on 10 July 2022. Retrieved 10 July 2022.
  65. ^ Bennett, J. C. (December 1973). "Visual observations of Comet Kohoutek 1973f". Monthly Notes of the Astronomical Society of Southern Africa. 32 (10, 11, 12): 107–108. Bibcode:1973MNSSA..32..107B. doi:10.1038/246400a0. S2CID 42320124.
  66. ^ a b Ferrín, Ignacio (1 August 2014). "The location of Oort Cloud comets C/2011 L4 Panstarrs and C/2012 S1 ISON on a comet evolutionary diagram". Monthly Notices of the Royal Astronomical Society. 442 (2): 1731–1754. arXiv:1306.5010. Bibcode:2014MNRAS.442.1731F. doi:10.1093/mnras/stu820. S2CID 54846398.
  67. ^ Gibson, Edward G. (December 1974). "Visual observations of Comet Kohoutek from Skylab III". Icarus. 23 (4): 493–501. Bibcode:1974Icar...23..493G. doi:10.1016/0019-1035(74)90012-8. S2CID 122741070.
  68. ^ a b c James, J. F. (April 1975). "What came out of Kohoutek's comet?". Nature. 254 (5499): 382–383. Bibcode:1975Natur.254..382J. doi:10.1038/254382b0. S2CID 4163458.
  69. ^ Skylab 1/4 Technical Air-to-Ground Voice Transcription. Houston, Texas: NASA. November 1973.
  70. ^ Kidger, Mark R. (1994). "The frequency of appearance of bright naked eye comets since 1750: Are bright comets less frequent in the 20th Century?". Earth, Moon, and Planets. 66 (2): 231–238. Bibcode:1994EM&P...66..231K. doi:10.1007/BF00644134. S2CID 119875072.
  71. ^ Marsden, Brian G.; Roemer, Elizabeth (March 1978). "Comets in 1974". Quarterly Journal of the Royal Astronomical Society. 19: 38–58. Bibcode:1978QJRAS..19...38M.
  72. ^ Hyder, Charles L.; Brandt, John C.; Roosen, Robert G. (December 1974). "Tail structure far from the head of Comet Kohoutek". Icarus. 23 (4): 601–610. Bibcode:1974Icar...23..601H. doi:10.1016/0019-1035(74)90028-1. S2CID 119997643.
  73. ^ Terenteva, A. K.; Kruchinenko, V. G.; Triashin, S. S. (July 1976). "Observations of meteors connected with comet Kohoutek, 1973f". Astronomicheskii Vestnik. 10 (1): 70–71. Bibcode:1976AVest..10...70T.
  74. ^ a b Eberhart, Jonathan (4 May 1974). "Eyes on the Comet". Science News. 105 (18): 290–291. doi:10.2307/3958991. JSTOR 3958991. S2CID 87707864.
  75. ^ a b c d Murdin, Paul, ed. (November 2000). "Computer Kohoutek (C/1973 E1)". Encyclopedia of Astronomy & Astrophysics (First ed.). Boca Raton, Florida: CRC Press. p. 771. Bibcode:2000eaa..bookE5239.. doi:10.1888/0333750888/5239. ISBN 9781000523034.
  76. ^ a b c d Rao, Joe (22 January 2020). "How the 'comet of the century' became an astronomical disappointment". Space.com. from the original on 8 April 2022. Retrieved 9 July 2022.
  77. ^ a b "Huge comet at Christmas to be visible". The Montreal Star. No. 81. Montreal, Quebec. 5 April 1973. p. 13. from the original on 20 September 2022. Retrieved 6 July 2022 – via Newspapers.com.  
  78. ^ "New comet holds brilliant hope for star-gazers". The Morning News. Vol. 183, no. 83. United Press International. 6 April 1973. p. 10. from the original on 20 September 2022. Retrieved 9 July 2022 – via Newspapers.com.  
  79. ^ Avery, Lorne (October 1973). "Orbital Data for Comet Kohoutek (1973f)". Journal of the Royal Astronomical Society of Canada Newsletter. 67: L25–L26. Bibcode:1973JRASC..67L..25A.
  80. ^ "Kohoutek Predictions Toned Down". Sentinel Star. No. 315. Associated Press. 11 November 1973. p. 22C. from the original on 20 September 2022. Retrieved 10 July 2022 – via Newspapers.com.  
  81. ^ Sullivan, Walter (17 January 1974). "Observations of Kohoutek Appear to Confirm Concept of Comets as 'snowballs'". The New York Times. New York. p. 24. from the original on 15 July 2022. Retrieved 15 July 2022.
  82. ^ Angione, Ronald J.; Gates, Bill; Henize, Karl G.; Roosen, Robert G. (January 1975). "The light curve of comet Kohoutek". Icarus. 24 (1): 111–115. Bibcode:1975Icar...24..111A. doi:10.1016/0019-1035(75)90164-5. S2CID 119799157.
  83. ^ Öpik, E. J. (September 1977). "On Predicting the Brightness of Comets". Irish Astronomical Journal. 13 (3/4): 92–94. Bibcode:1977IrAJ...13...92O.
  84. ^ Sekanina, Zdenek (1976). "A Continuing Controversy: Has the Cometary Nucleus been Resolved?". International Astronomical Union Colloquium. 25 (2): 537–587. doi:10.1017/S0252921100034084. hdl:2060/19760013988.
  85. ^ Whipple, Fred L. (1975). "Implications for Models and Origin of the Nucleus". In Gary, Gilmer (ed.). Comet Kohoutek: A Workshop Held at Marshall Space Flight Center. Washington, D.C.: NASA. pp. 227–232.
  86. ^ Whipple, Fred L. (1985). "Present Status of the Icy Conglomerate Model". In Klinger, Jürgen; Benest, Daniel; Dollfus, Audouin; Smoluchowski, Roman (eds.). ICES in the Solar System. Mathematical and Physical Sciences, Volume 156. D. Reidel Publishing Company. pp. 343–366. doi:10.1007/978-94-009-5418-2_23. ISBN 9789401088916.
  87. ^ Ip, W.-H.; Mendis, D. A. (September 1973). "Development of an H
    2    O     Atmosphere around Comet Kohoutek (1973f) and its Possible Detection". Nature. 245 (5422): 197–199. Bibcode:1973Natur.245..197I. doi:10.1038/245197a0. S2CID 4245004.
  88. ^ a b c Whipple, Fred L. (September 1976). "Background of modern comet theory". Nature. 263 (5572): 15–19. Bibcode:1976Natur.263...15W. doi:10.1038/263015a0. S2CID 40079180.
  89. ^ a b Wehinger, P. A.; Wyckoff, S.; Herbig, G. H.; Herzberg, G.; Lew, H. (May 1974). "Identification of H
    2    O+
     in the Tail of Comet Kohoutek (1973f)". The Astrophysical Journal. 190: L43. Bibcode:1974ApJ...190L..43W. doi:10.1086/181500. S2CID 121346176.
  90. ^ a b c Metz, William D. (27 July 1973). "Kohoutek, the Christmas Comet: Skylab Mission Expanded?". Science. 181 (4097): 333–334. Bibcode:1973Sci...181..333M. doi:10.1126/science.181.4097.333. JSTOR 1736609. PMID 17832027. S2CID 31602518.
  91. ^ Krankowsky, Dieter (1991). "Section V: The Cometary Coma". The Composition of Comets. Vol. 116. Cambridge University Press. pp. 854–877. Bibcode:1991ASSL..167..855K. doi:10.1017/S0252921100012744. {{cite book}}: |journal= ignored (help)
  92. ^ Brandt, John C. (1 October 1981). The JOCR Program (PDF). JPL Mod. Observational Tech. for Comets (Report). NASA. pp. 171–184. (PDF) from the original on 15 July 2022. Retrieved 15 July 2022.
  93. ^ "June". Astronautics and Aeronautics, 1973: Chronology of Science, Technology, and Policy. Washington, D.C.: NASA. 1975. p. 191. from the original on 14 July 2022. Retrieved 14 July 2022.
  94. ^ Sullivan, Walter (16 June 1973). "Plan to 'Intercept' Comet For Close Study Weighed". The New York Times. New York. p. 56. from the original on 14 July 2022. Retrieved 14 July 2022.
  95. ^ "Skylab 3 to study a brilliant comet". The New York Times. Associated Press. 17 August 1973. p. 18. from the original on 14 July 2022. Retrieved 14 July 2022.
  96. ^ Lundquist, Charles A. (ed.). "4. Observations of Comet Kohoutek". Skylab's Astronomy and Space Sciences. Washington, D.C.: NASA. from the original on 13 November 2004. Retrieved 9 July 2022.
  97. ^ Mars, Kelli, ed. (5 February 2019). "45 Years Ago: Mariner 10 flies by Venus". NASA History. NASA. from the original on 10 July 2022. Retrieved 8 July 2022.
  98. ^ Dunne, James A.; Burgess, Eric (1978). "5. Venus Bound - Success and Near Failure". The Voyage of Mariner 10. Washington, D.C.: NASA. from the original on 24 January 2021. Retrieved 14 July 2022.
  99. ^ "Pioneer 06". Solar System Exploration. NASA. 11 August 2019. from the original on 12 July 2022. Retrieved 14 July 2022.
  100. ^ Roemer, E. (18 June 1976). "Operation Kohoutek". Science. 192 (4245): 1227. Bibcode:1976Sci...192.1227R. doi:10.1126/science.192.4245.1227. JSTOR 1742598. PMID 17771755. S2CID 34080360.
  101. ^ Sullivan, Walter (24 December 1973). "Revised Theory on Comets Offered". The New York Times. New York. p. 30. from the original on 8 July 2022. Retrieved 8 July 2022.
  102. ^ "Reports in Brief". South African Journal of Science. 71. December 1975. from the original on 20 September 2022. Retrieved 8 July 2022.
  103. ^ Brim, Nancy L. (1977). Astronautics and Aeronautics, 1974 (Technical report). NASA History Series. NASA. Bibcode:1977NASSP4019.....B. NASA SP-4019.
  104. ^ Mendis, D. A.; Brin, G. D. (December 1977). "Monochromatic brightness variations of comets: II.Core-Mantle Model". The Moon. 17 (4): 359–372. Bibcode:1977Moon...17..359M. doi:10.1007/BF00562645. S2CID 119797846.
  105. ^ Iju, Tomoya; Abe, Shinsuke; Tokumaru, Munetoshi; Fujiki, Ken’ichi (May 2015). "Plasma distribution of Comet ISON (C/2012 S1) observed using the radio scintillation method". Icarus. 252: 301–310. arXiv:1410.2119. Bibcode:2015Icar..252..301I. doi:10.1016/j.icarus.2015.02.007. S2CID 118607736.
  106. ^ Lee, L. C. (November 1976). "Plasma irregularities in the comet's tail". The Astrophysical Journal. 210: 254–257. Bibcode:1976ApJ...210..254L. doi:10.1086/154825. hdl:2060/19760012963. S2CID 120556703.
  107. ^ a b Safire, William (30 July 1973). "Kohoutek's Comet". The New York Times. New York. p. 27. from the original on 7 July 2022. Retrieved 7 July 2022.
  108. ^ Stern, Jane; Stern, Michael (1992). "Kohoutek". Jane & Michael Stern's Encyclopedia of Pop Culture: An A to Z Guide of Who's who and What's What, from Aerobics and Bubble Gum to Valley of the Dolls and Moon Unit Zappa (1st ed.). New York: HarperPerennial. pp. 266–268. ISBN 9780060553432.
  109. ^ a b c Warwick, Ronald W. (1999). "Trafalgar House, Cunard, and the QE2". QE2: The Cunard Line Flagship, Queen Elizabeth II (3rd ed.). New York: W.W. Norton & Co. p. 97. ISBN 9780393047721.
  110. ^ a b Segal, Jonathan (4 November 1973). "Science Cruises Becoming Popular". The New York Times. New York. p. 624. from the original on 14 July 2022. Retrieved 14 July 2022.
  111. ^ Barney, Lillian (2 December 1973). "'Comet of Century' to Get Dim Showing Over L.I." The New York Times. New York. p. 164. from the original on 14 July 2022. Retrieved 14 July 2022.
  112. ^ Schuman, Wendy (16 December 1973). "Star Fails to Show For QE2 Gazers". The New York Times. New York. p. 137. from the original on 14 July 2022. Retrieved 14 July 2022.
  113. ^ a b c d e Carlinsky, Dan (26 December 1973). "Business Boomlet Trailing Kohoutek". The New York Times. p. 65. from the original on 14 July 2022. Retrieved 14 July 2022.
  114. ^ Asimov, Isaac (1995). "Cruises". I. Asimov: A Memoir (Bantam pbk. ed.). New York: Bantam. p. 365. ISBN 9780553569971.
  115. ^ "Travel Notes: Survey Of Restrictions on Driving in Europe". The New York Times. New York. 9 December 1973. p. 594. from the original on 14 July 2022. Retrieved 14 July 2022.
  116. ^ "Colleges Aid Comet Watchers". The New York Times. New York. 16 December 1973. from the original on 14 July 2022. Retrieved 14 July 2022.
  117. ^ Weiner, Lawrence (March 1974). "On the Comet Kohoutek". American Journal of Psychiatry. 131 (3): 331–c–332. doi:10.1176/ajp.131.3.331-c. PMC 4812706. PMID 26951657.
  118. ^ a b Perlman, David (1974). "Science and the Mas Media". Daedalus. 103 (3): 207–222. JSTOR 20024229.
  119. ^ a b c Eicher, David J. (2013). Comets!: Visitors from Deep Space. New York: Cambridge University Press. ISBN 9781107513501.
  120. ^ a b Fiske, Edward B. (24 December 1973). "Fundamentalists View 'Christmas Comet' as a Sign". The New York Times. New York. from the original on 14 July 2022. Retrieved 14 July 2022.
  121. ^ "Welcoming 'the age of Kohoutek'". San Francisco Examiner. Vol. 1974, no. 4. 27 January 1974. p. 3. from the original on 20 September 2022. Retrieved 15 July 2022 – via Newspapers.com.  
  122. ^ Hoopes, John W. (January 2011). "A critical history of 2012 mythology". Proceedings of the International Astronomical Union. 7 (S278): 240–248. Bibcode:2011IAUS..278..240H. doi:10.1017/S174392131101266X. S2CID 194041975.
  123. ^ MacPherson, Les (4 January 2013). "Comet's arrival may be a flop". Regina Leader-Post. Regina, Saskatchewan. from the original on 14 July 2022. Retrieved 14 July 2022.
  124. ^ Evans, Ben (2012). At Home in Space: The Late Seventies into the Eighties. New York: Springer Science+Business Media, LLC. ISBN 9781441988102.
  125. ^ Baker, Russell (15 January 1974). "The Cosmic Flopperoo". The New York Times. New York. p. 37. from the original on 15 July 2022. Retrieved 15 July 2022.
  126. ^ Carroll, Peter N. (1990). ""To Heal the Fragmentations": Redefining Authority at Mid-Decade". It Seemed Like Nothing Happened: America in the 1970s. New Brunswick, New Jersey: Rutgers University Press. pp. 13–14. ISBN 9780813515380.
  127. ^ Greenberg, Annie. "Kohoutek Planning Commences" (PDF). The Other Side. Vol. 14, no. 2. Claremont, California. pp. 1–3. (PDF) from the original on 20 September 2022. Retrieved 15 July 2022.
  128. ^ Rojas, Luca (30 April 2010). "Kohoutek Music Festival Goes Big with GZA". The Student Life. from the original on 27 July 2021. Retrieved 15 July 2022.
  129. ^ Bainbridge, William Sins (2015). "The Impact of Space Exploration on Public Opinions, Attitudes, and Beliefs". In Dick, Steven J. (ed.). Historical Studies in the Societal Impact of Spaceflight (PDF). Washington, D.C.: NASA. p. 21. (PDF) from the original on 1 October 2020. Retrieved 15 July 2022.
  130. ^ Karam, P. Andrew (2017). Comets: nature and culture. London: Reaktion Books. ISBN 9781780238586.
  131. ^ Hegarty, Paul; Halliwell, Martin (2011). "Progressive Fusion". Beyond and Before: Progressive Rock Since the 1960s. New York: Bloomsbury Publishing. p. 115. ISBN 9780826423320.
  132. ^ Madrid, Alejandro L. (2015). "Experimentalism, Mythology". In Search of Julián Carrillo and Sonido 13. New York: Oxford University Press. p. 223. ISBN 9780190215781.
  133. ^ The Defenders #15 (September 1974), Marvel Comics

External links edit

  • C/1973 E1 at the JPL Small-Body Database  
    • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters
 
Wikimedia Commons has media related to Comet Kohoutek.

January 01, 1970
comet, kohoutek, confused, with, short, period, comet, kohoutek, formally, designated, 1973, formerly, 1973, 1973f, comet, that, passed, close, towards, 1973, early, predictions, comet, peak, brightness, suggested, that, potential, become, brightest, comets, 2. Not to be confused with the short period comet 75D Kohoutek Comet Kohoutek formally designated C 1973 E1 and formerly as 1973 XII and 1973f c is a comet that passed close to the Sun towards the end of 1973 Early predictions of the comet s peak brightness suggested that it had the potential to become one of the brightest comets of the 20th century capturing the attention of the wider public and the press and earning the comet the moniker of Comet of the Century Although Kohoutek became rather bright the comet was ultimately far dimmer than the optimistic projections its apparent magnitude peaked at only 3 as opposed to predictions of roughly magnitude 10 and it was visible for only a short period quickly dimming below naked eye visibility by the end of January 1974 d C 1973 E1 Kohoutek Comet Kohoutek on 11 January 1974 as seen from Catalina ObservatoryDiscoveryDiscovered byLubos KohoutekDiscovery date18 March 1973DesignationsPronunciation k oʊ ˈ h uː t ɛ k ko HU tek k oʊ h oʊ t ɛ k ko ho tek a Alternative names1973f 1973 XIIOrbital characteristics 4 Epoch 24 December 1973 JD 2442040 5 Observation arc1 24 years 594 observations Aphelion98000 AU inbound 3700 AU outbound 4 Perihelion0 1424249 AU 5 Eccentricity0 999997 inbound 0 99992 outbound 4 Orbital period sidereal 11 million yr inbound 80 thousand yr outbound 4 Inclination14 30426 Longitude of ascending node258 48953 Time of perihelion28 December 1973 5 6 Argument of perihelion37 79761 Earth MOID0 029043 AU 4 34 million km 6 Physical characteristicsMean diameter4 2 km 2 6 mi 7 Albedo0 67 7 b Apparent magnitude 3 1973 perihelion 0 peak for ground observers 8 Absolute magnitude H 5 8 total 9 5 nucleus The comet was discovered by and named after Lubos Kohoutek at the Hamburg Observatory on 18 March 1973 Kohoutek had been searching for Biela s Comet and had serendipitously discovered his eponymous comet while reviewing photographic plates for a different object The comet was discovered farther away from the Sun than any previous comet Conventional practices for predicting comet brightness led to generous projections of Comet Kohoutek s luminosity towards the end of 1973 and the beginning of 1974 leading to great anticipation within both scientific circles and the general public Comet Kohoutek reached perihelion on 28 December 1973 Though the comet was then at its brightest it could only be observed by scientific instrumentation and astronauts on Skylab For most ground observers Kohoutek only reached as bright as magnitude 0 when it emerged from the Sun s glare in January 1974 It quickly faded beyond naked eye visibility later that month and was last observed in November 1974 Due to its underwhelming brightness after intense publicity Kohoutek became synonymous with spectacular disappointment Because of its early detection and unique characteristics numerous scientific assets were dedicated to observing Kohoutek during its 1973 74 traversal of the inner Solar System making Kohoutek the most well studied comet at the time the resulting findings significantly advanced the understanding of comets The identification of larger and more complex molecules emanating from Kohoutek alongside related but simpler chemical species confirmed the hypothesis that comets were composed of larger molecules that dissociated into simpler products The significant presence of gasses and plasma expelled from Kohoutek supported the longstanding dirty snowball hypothesis concerning the composition of comet nuclei The detection of water e methyl cyanide hydrogen cyanide and silicon in Kohoutek were the first time such chemical species were observed in any comet Its underwhelming display challenged longstanding assumptions regarding the light curve of similar comets entering the inner Solar System Kohoutek s highly eccentric orbit preceding its 1973 perihelion suggests that it may have been formed early in the formation of the Solar System or it may have originated from a different planetary system Its orbital period may have been initially in the order of several million years or its 1973 apparition may have been its first trek into the inner Solar System Its nucleus has an estimated average radius of 2 1 km 1 3 mi 7 Contents 1 Discovery 2 Orbit 3 Structure and composition 4 Observational history 5 Brightness predictions 6 Observing campaigns and scientific results 7 Media coverage and viewing events 8 Cultural impact 9 See also 10 Notes 11 References 12 External linksDiscovery edit nbsp Lubos Kohoutek eponymous discoverer of Comet Kohoutek at the mission control center at Johnson Space Center speaking with the astronauts of Skylab 4 during the passage of the comet in January 1974 The comet was discovered on 18 March 1973 by Czech astronomer Lubos Kohoutek after reviewing twice exposed photographic plates taken by the 80 cm 31 in aperture Schmidt camera at the Hamburg Observatory in Bergedorf on 7 March and 9 March The object remained evident and was displaced slightly towards the west northwest in the latter plate confirming that it was moving against the background stars and not a transient or erroneous feature 11 1 1 Upon discovery the comet had an apparent magnitude between 15 5 and 16 and lay in the constellation of Hydra Kouhoutek described the comet as initially diffuse with central condensation 12 13 The comet was located near the orbit of Jupiter around the time of discovery 4 7 astronomical units AU away from the Sun and 4 AU from the Earth 14 11 As a result the comet was moving very slowly towards the west northwest at around 0 2 per day 15 Based on subsequent orbital calculations the discovery of the comet occurred roughly seven months before perihelion 16 The discovery of a comet at such large distances and long leadtimes before their perihelia was unprecedented 17 18 12 at the time comets were rarely discovered at such large distances from the Sun as most were too faint to be detected 19 Kohoutek transmitted his findings to the Central Bureau for Astronomical Telegrams on 19 March leading to the announcement of his discovery in circular 2511 of the International Astronomical Union It was the sixth comet discovered in 1973 and thus given the designation 1973f 12 1 3 Due to increasing public attention towards the comet the comet was also named Comet Kohoutek in honor of its discoverer Lubos Kohoutek 1 3 The comet s discovery was serendipitous beginning in 1971 Kohoutek had been searching for Biela s Comet which had not been observed since 1852 Using the Hamburg Observatory s Schmidt camera the initial search in October and November 1971 found 52 minor planets in a roughly 180 square degree region of the sky Preliminary orbits were determined for 35 of these newly found objects of which 15 were targeted for observation between January and April 1973 The 7 March photographic plate was intended to feature one of the objects main belt asteroid 1971 UG f but instead captured Comet Kohoutek 12 Comet Kohoutek was later precovered on a photographic plate taken on 28 January exhibiting a similar brightness as during its discovery and a heliocentric distance of 5 2 AU 14 15 The plate was also taken in pursuit of 1971 UG 15 The comet was the second discovered by Kohoutek in 1973 the first had been discovered on 28 February during the same search for Biela s Comet and was also found on a photographic plate that was intended to contain another of the newly discovered minor planets 12 g Orbit edit nbsp The orbits and timings of Comet Kohoutek near its perihelion in red and the Earth in blue Orbital elements for Comet Kohoutek were calculated by British astronomer Brian G Marsden soon after the comet s discovery using photographic plates taken of the comet on 7 March 9 March and 21 March 12 These calculations suggested that Kohoutek had a nearly parabolic orbit lying close to the ecliptic with an eccentricity between 0 9999 and 1 and an inclination of 14 3 Such an orbit meant that the comet would approach very close to the Sun with perihelion occurring on 28 December 1973 at a distance of only 0 14 AU 5 The close perihelion and the comet s brightness upon discovery were analogous to other comets that had become very bright The calculated orbit also suggested that Kohoutek s close pass of the Sun could be its first traversal of the inner Solar System 14 13 Marsden s calculated orbit placed Kohoutek s initial semi major axis at 50 000 AU 22 4 Alternatively Kohoutek may have had an orbital period of 4 million years before experiencing the gravitational perturbations from the Solar System s planets which would make Kohoutek a long period comet 23 This idea was supported by Stephen P Maran the head of NASA s efforts to study Kohoutek Maran believed that the comet initially had a perihelion farther out than the orbit of Jupiter until it was gravitationally perturbed by a passing star lowering its perihelion to within the orbit of Mercury and its orbital period to 4 5 million years additional gravitational interactions between the comet and the planets would have shortened the comet s orbital period further to about 75 000 years 24 4 The closest approach of Kohoutek to Earth occurred on 15 January 1974 and be no nearer than 0 8 AU preventing the resolution of its nucleus via Earth based instruments 25 26 Both the Minor Planet Center and the JPL Small Body Database list Kohoutek as having a hyperbolic trajectory when it was near perihelion 5 6 but the orbit became bound to the Sun by 1978 27 The comet is not expected to return for about 75 000 years 4 Some of the meteoroids ejected by Kohoutek during its initial approach particularly those with diameters no smaller than 0 2 mm 0 0079 in were placed into stable orbits around the Sun 28 As seen from Earth between 1973 and 1974 the comet took a southeastward path across the sky similar to Comet Halley s path between 1985 and 1986 The visibility of the comet was most favorable to observers in the Southern Hemisphere and the tropics It was in the evening sky from the time of its discovery to the end of September 1973 after which the comet became a morning sky object After being positioned in Hydra upon the time of discovery Comet Kohoutek moved across the constellations of Sextans Leo Crater Corvus Virgo Libra Scorpius and Sagittarius by the end of 1973 Kohoutek was near the boundary of Sagittarius and Ophiuchus during perihelion when it was visually separated from the Sun by only 0 5 In 1974 the comet moved across the constellations of Capricorn Aquarius Pisces and Taurus 11 13 As of 2022 update comet Kohoutek is about 74 AU 11 billion km from the Sun in the constellation of Gemini 29 It is currently receding from the Sun at 4 8 km s 11 000 mph 29 Structure and composition edit nbsp False color image of Comet Kohoutek as photographed with a far ultraviolet electrographic camera during a Skylab spacewalk on 25 December 1973 Kohoutek s highly eccentric orbit and possible lack of prior planetary or solar interactions suggest that the comet may have been a primordial body of either the Solar System or that it may have originated from another planetary system 23 The comet may have also originated from the Oort cloud 19 A 1976 analysis of photometry and water loss rates estimated that the nucleus had a radius of around 2 1 km 1 3 mi and an albedo of around 0 67 7 A photometric analysis of Kohoutek using Mercury as a reference established an upper limit of 30 km 19 mi for the diameter of Kohoutek s nucleus 30 An attempt to detect a radar echo from Kohoutek s nucleus using the Haystack Radio Telescope received no radar returns constraining the nucleus s size to under 250 km 160 mi 31 The comet has a total absolute magnitude at 1 AU of 5 8 and a nuclear absolute magnitude of 9 5 6 During Kohoutek s 1973 74 apparition its tail s width ranged from around 30 000 km 19 000 mi near the coma to 300 000 km 190 000 mi farther away Detection of positive carbon monoxide ions showed that the tail was at least 20 million km 12 million mi in length 32 A more yellow and orange appearance of the dust tail of Kohoutek during its perihelion as observed by astronauts on Skylab was likely the result of light scattering by basaltic dust particles with sizes of around 0 5 mm The tail lacked color closer to the coma near perihelion indicating a large distribution of particle sizes and resulting in a white appearance 33 Observations from the Joint Observatory for Cometary Research in Socorro New Mexico were able to trace the blue ion tail of Kohoutek featuring more prominently than the comet s dust tail to a distance of 0 333 AU 49 800 000 km 31 000 000 mi away from the nucleus 34 The particle density within the tail several million miles away from the nucleus was about 10 ions per cubic centimeter while the maximum electron density within the tail was around 20 000 electrons per cubic centimeter 32 35 At a distance of around 0 5 AU from the Sun the plasma outflow in Kohoutek s tail generated a weak magnetic field with a strength comparable to the interplanetary magnetic field 36 nbsp Sequence of images of Kohotuek at perihelion taken via coronagraph Analyses of Kohoutek have provided different assessments of the scale of the comet s release of dust and gas with some suggesting that Kohoutek is relatively dust rich and consequently gas poor and others suggesting that the comet is relatively dust poor and consequently gas rich 37 14 Between 16 and 29 January 1974 the nucleus was expelling roughly 1 675 kg of gas and 16 000 kg of dust per second on average 37 38 The predominance of dust was thought to have been demonstrated by the emergence of an antitail when the Earth passed through the plane of Kohoutek s orbit antitails are composed of relatively large solid particles that disperse around the nucleus 19 Particles in the antitail had radii larger than approximately 10 mm while particle radii in the coma and tail were less than 1 mm At a distance of 0 23 AU from the Sun the less reflective material in the coma had an effective temperature of 720 20 K while the material in the antitail featured effective temperatures of 565 10 K 39 Intense solar heating near the time of perihelion greatly reduced the size of particles in the antitail leaving behind only particles with initial sizes of at least 100 150 mm and leading to a decrease in the antitail s brightness following perihelion 40 Silicates were also detected in the tail and antitail via infrared astronomy 19 41 42 On 2 December 1973 Kohoutek was expelling about 900 billion dust molecules per second However Kohoutek became less dusty following perihelion with dust production lowering to around 30 billion dust molecules per second on 31 January 1974 41 This transition was also underscored by an increase in the gas to dust ratio of Kohoutek by at least a factor of 2 after perihelion 43 The change may have been enabled by the evaporation of ice covered surfaces as Kohoutek drew closer to the Sun 7 The ejection of meteoroids during Kohoutek s approach and passage of the Sun added about 1 billion kg of mass to the zodiacal cloud 28 Smaller micrometeoroids were detected by the HEOS 2 satellite when it crossed the orbital plane of the outgoing comet around 9 June 1974 with the micrometeoroids being detected over the course of around 60 days surrounding the plane traversal these micrometeoroids had masses ranging between 10 13 10 11 g 44 45 nbsp Kohoutek as seen from Skylab in December 1973 Later photometric analyses indicated that Kohoutek was a gassy comet with a high gas to dust ratio emblematic of comets entering the inner Solar System for the first time suggesting a nucleus rich in volatiles and relatively depleted in refractory substances 37 46 Analyses of Kohoutek s coma and tail in the near ultraviolet found the roughly equal presence of hydrogen atoms and hydroxide suggesting that these chemical species were once constituents of water At a distance of 1 AU from the Sun Kohoutek was losing roughly 1 million tons 0 9 million tonnes of water per day 19 The mass of water lost between 60 days before perihelion to 60 days after perihelion when Kohoutek would have been ejecting the most water was approximately 64 billion kg 7 The mass loss due to the ejection of water after perihelion was roughly two times less than before perihelion The surface of Kohoutek s nucleus was likely covered in a mix of particles and water ice stored in clathrates Much of this water was evaporated away as Kohoutek approached perihelion due to increased insolation leaving behind only subsurface ices and smaller pockets of water on the nuclear surface 7 The uneven outgassing behavior of both water and other volatiles indicates that Kohoutek s nucleus likely has a heterogeneous composition and structure on scales of around 10 m 33 ft Jets of vaporizing volatiles likely emanated from exposed areas where less volatile ices previously vaporized 47 Later analysis of spectrograms of Kohoutek provided strong evidence of the presence of the water cation H2 O particularly in the comet s tail 48 49 This chemical species was most likely the result of the photoionization of neutral water H2 O very near the nucleus 50 51 Atomic oxygen and atomic carbon were also detected as the likely products of dissociating carbon monoxide or carbon dioxide from the nucleus 52 The nucleus also outgassed hydrogen at rates of up to approximately 4 5 1029 atoms per second at speeds of around 7 8 0 2 km s 53 54 Due to the low mass of hydrogen and the weak gravitational pull of Kohoutek the cloud of hydrogen surrounding the comet was of great extent extending over 30 million km 19 million mi across 53 55 the hydrogen cloud was thus larger than the disk of the Sun 56 Within the cloud the ratio of deuterium to atomic hydrogen was at most 1 percent 54 The atomic hydrogen was later understood to be the product of the photodissociation of water ice present in Kohoutek s nucleus 57 The nucleus may also have been once covered by a roughly meter thick layer of highly volatile substances that quickly outgassed when Kohoutek first approached the inner Solar System 22 Cyanide was first observed within Kohoutek s coma on 15 October 1973 while the comet was at a heliocentric distance of 1 8 AU 14 The spectrographic signature of methyl cyanide at a wavelength of 2 7 mm was also detected in the nucleus of Kohoutek 58 Radio and microwave observations of the comet identified hydrogen cyanide methylidyne radicals and ethyl alcohol in addition to hydroxide and water 19 59 60 Other chemical species identified in the inner coma of Kohoutek included the amino radical diatomic carbon and sodium iodide 61 62 Emission signatures of tricarbon and nitrogen gas were also detected 62 63 Unlike in previously observed comets the cyano radicals and diatomic carbon in Kohoutek s coma were not distributed spherically but instead elongated significantly away from the sun to distances of up to 10 000 000 km 6 200 000 mi 62 Observational history edit nbsp Kohoutek as seen from the Kitt Peak National Observatory on 28 April 1973 Following Lubos Kohoutek s discovery of his eponymous comet additional photographic observations taken on 30 March and 2 April 1973 showed that the comet s coma was highly condensed and 20 arcseconds in diameter The comet was last observed by Kohoutek on 5 May 1973 before it became too faint and unremarkable to observe or discern against the glare of twilight 11 At this stage the comet s brightness was around magnitude 14 64 After several months of poor visibility the comet was detected by Japanese astronomer Tsutomu Seki on 23 September the comet s apparent magnitude had brightened to magnitude 11 but it remained a diffuse object 11 By the time the comet was recovered it had neared to a distance of 2 2 AU away from the Sun 15 While the comet previously appeared as only a faint featureless nebulosity by late September a tail had become conspicuous appearing first in a broad and fan like form extending 2 arcminutes to the north 15 The coma grew to about 1 arcminute in diameter by mid October 1973 as the comet brightened By the end of the month both the nucleus and a lengthening tail had become clearly apparent 65 In November 1973 Kohoutek became bright enough to be visible to the naked eye 13 The ion component of the comet s tail was first noted on 21 November accompanying the brighter dust component 15 The comet brightened to an apparent magnitude of 2 8 by 22 December 1973 before becoming indiscernible to ground based observers due to Kohoutek s conjunction with the Sun 13 between 24 and 31 December the comet was within 10 of the Sun 11 During this period the comet experienced a surge in brightness that although not clearly observable from the Earth s surface placed it in the echelon of great comets 66 Kohoutek was at its brightest during this period becoming a roughly 3rd magnitude object 11 Kohoutek was a much brighter object in the infrared reaching magnitudes of at least 4 75 and 5 70 at wavelengths of 10 microns and 20 microns respectively 62 At its closest approach the comet was visually separated by only around 0 75 from the center of the Sun 15 While the comet was too close to the Sun to be discernible from the ground astronauts on Skylab and Soyuz 13 were able to observe the comet during its perihelion 64 The astronauts on Skylab noted that the comet was distinctly yellow and estimated that Kohoutek at its brightest was comparable to the magnitude 1 6 brightness of Jupiter 11 An antitail emerged during Kohoutek s close passage stretching as far as 5 7 from the comet towards the Sun 15 The separate gas and dust tails typically seen on comets were not observed from Skylab instead the comet uniformly took on a yellow texture transitioning to white and later to a mottled violet appearance 67 The strikingly yellow color of the comet at perihelion was due to the scattering of sunlight by sodium released by the comet 68 nbsp Illustration of Kohoutek on 29 December 1973 by Skylab 4 s Edward Gibson nbsp Progressive views of Comet Kohoutek as viewed by SL4 astronauts I just finished taking the 233 photos and Kohoutek is not looking like our old pretty graceful looking blue white comet any more It s getting so close to the Sun now that the tail is fanning out it s very short I think I can t see the rest of the tail just because it s so light But what I can see behind the comet now the the coma is getting quite large and bright and the tail all we can see is a fan behind it And we re beginning to see some reds and some yellows in it Gerald P Carr speaking to NASA Mission Control Center on 25 December 1973 Skylab Air to Ground Voice Transcription Tape MC1309 1 69 Kohoutek once again became observable to ground based observers beginning on 27 December 1973 For ground observers the comet was at most a 0th or 1st magnitude object 11 By the time Kohoutek had reached a more favorable position for viewing by the general public it had faded to around magnitude 2 64 Although the comet was dimmer than anticipated it was nonetheless among the ten brightest comets as seen from Earth between 1750 and 1994 70 The comet rapidly dimmed following its perihelion on 28 December diminishing to magnitude 1 5 on 1 January 1974 and reaching magnitude 4 by 10 January 1974 By the end of January 1974 Kohoutek was too faint to be seen with the unaided eye 13 The comet dimmed to around 10th magnitude towards the end of March 1974 after which it became too faint to clearly detect against the backdrop of the zodiacal light 11 Unlike on the comet s inbound trek its appearance on the outbound trek was much more diffuse and nebulous 71 When the comet returned to the same distance from the Sun at which it was discovered it was over 100 times fainter than at its first detection 22 The comet was last photographed in early November 1974 at a heliocentric distance of around 5 AU with an apparent magnitude of 22 64 At its greatest visual extent Kohoutek s tail was well defined and spanned 25 in length 13 In January 1974 its tail featured both a helical structure and a more irregular cloud like structure about 0 1 AU away from the nucleus 72 Kohoutek s antitail spanned as much as 3 for ground observers 13 the antitail became more diffuse and dim following perihelion making its visibility less favorable 68 A faint meteor shower seen on 1 3 March 1974 concurrent with Earth s closest pass of Kohoutek s orbit may have been directly associated with Kohoutek 73 Brightness predictions edit nbsp The light curve of Kohoutek plotted from ground based observations with the perihelion denoted by the red line While initial predictions assumed the comet s luminosity would scale to the 4th or even 6th power of its heliocentric distance its brightness on approach scaled more closely with the second power Kohoutek s anticipated close passage of the Sun and its pristine condition having likely never approached the Sun previously made the comet a candidate for becoming one of the brightest comets of the 20th century Conventional wisdom held that the brightness of a comet was scaled according to the inverse fourth power of its distance from the Sun and it was customary at the time to use this assumption in predicting the peak brightnesses of newly discovered comets 10 The value of the power denoted n would be repeatedly changed in subsequent estimates from the conventional value of 4 with estimates generally using values of n between 3 6 74 Kohoutek s distance at the time of its discovery meant that its intrinsic brightness could increase by more than a million fold using these assumptions 19 While a more accurate estimate for the comet s ultimate apparent brightness around magnitude 2 3 could be derived from early observations 12 some of the first extrapolations of the comet s brightness using the initial photographic observations predicted apparent magnitudes as bright as magnitude 10 near perihelion such a remarkably bright comet would be visible in daylight Estimates later reached as bright as magnitude 12 comparable to the brightness of the full Moon The high peak luminosity also implied ample visibility early projections showed Kohoutek reaching naked eye visibility in early November and then becoming as bright as Jupiter by mid December with increasing brilliance in January 1974 following its perihelion Kohoutek was billed by the press as the Comet of the Century when these estimates were publicized 11 24 75 76 Fred Lawrence Whipple also remarked that the comet could well be the comet of the century 3 1 Brian Marsden stated that an object as large as Comet Kohoutek should achieve unusual brightness and produce an exceptional tail with twelve weeks of naked eye visibility but also cautioned that some very promising comets of the past have fizzled out 77 78 The Associated Press reported in early April 1973 that astronomers believed that the comet s approach could be the most spectacular astrophysical event of the 20th century 77 nbsp Kohoutek s brightness observations plotted as points fell short of predictions based on the light curves of past comets like Arend Roland and Bennett the solid and dashed lines respectively Although the most bullish predictions caught the attention of the press and the general public some astronomers like S W Milbourn and Whipple were more uncertain and held that such predictions were optimistic 11 19 Regardless of its luminosity the comet would be too close to the sun to be seen by ground observers at its brightest 74 British Astronomical Association BAA circular 548 published on 25 July 1973 provided an alternative prediction of magnitude 3 for Kohoutek s peak brightness 11 Higher end projections of Kohoutek s peak brightness remained as high as magnitude 10 into August 1973 An article in Nature published in the final week of September 1973 suggested that Kohoutek s peak brightness could have a greater than 50 percent chance of being within two magnitudes of 4 25 The National Newsletter accompanying the Journal of the Royal Astronomical Society of Canada in October 1973 estimated that Kohoutek would remain visible to the naked eye for four months bracketing perihelion 79 Brightness predictions were revised downward following the comet s behavior as perihelion approached 16 On 11 October 1973 BAA circular 549 provided a revised estimate of magnitude 4 for Kohoutek s brightest apparent magnitude While still bright such a brightness would yield only around ten days of clear naked eye visibility for observers in the Northern Hemisphere 11 Publicized predictions of the comet were scaled back in November 1973 80 Although Kohoutek brightened by a factor of nearly a million by perehelion sufficiently to be a fine object for experienced observers when seen under ideal conditions in clear skies away from city lights according to Whipple its peak magnitude of 3 fell short of the most publicized projections and proved mediocre to the public eye 19 22 however the comet s ultimate brightness was close to the published lower end predictions 11 Whipple later quipped that if you want to have a safe gamble bet on a horse not a comet 81 Despite higher assumed values of n the light curve of Kohoutek from 24 November 1973 to perihelion best fit n 2 2 while its light curve after perihelion to 16 January 1974 best fit n 3 3 or n 3 8 82 The more optimistic use of n 6 led to overestimates of Kohoutek s perihelion brightness by as much as a factor of 2800 83 The early brightness of Kohoutek around the time of its discovery may have been influenced by the intense outgassing of highly volatile substances such volatiles may have been abundant in the nucleus if Kohoutek had never previously entered the inner Solar System 75 84 The degree of outgassing may have been enhanced by extremely porous outer layers of the nucleus that readily allowed the most volatile ices to vaporize at great distances from the Sun 85 In this model the comet would have brightened quickly in the early stages of its solar approach at about n 5 78 before brightening more in line with shorter period comets 66 22 The early burst would have led to inflated expectations for the comet s ultimate brightness 76 A separate study of long period comets published in 1995 found that comets with initial semi major axes greater than 10 000 AU brighten more slowly and less substantially before perihelion than shorter period comets 10 Such comets are discovered at farther distances from the Sun than other comets as a result 86 It is now understood that Kohoutek s light curve preceding its 1973 perihelion was typical for comets with similar orbits 10 Observing campaigns and scientific results edit nbsp Artist s concept of Skylab 4 astronauts observing Comet Kohoutek via the space station s airlock Kohoutek was the subject of intense scientific investigation and was observed over an unprecedentedly large range of the electromagnetic spectrum 14 Kohoutek represented the first time radio astronomy techniques were used to study a comet 19 The possibility that the comet could be entering the inner Solar System for the first time since its formation making it potentially illustrative of the evolution of comets and conditions in the early Solar System made it an attractive scientific target 18 12 The comet s exceptionally early detection as well as the concurrence of its perihelion with Skylab 4 allowed for and motivated the coordination of Operation Kohoutek a cometary observing campaign backed by NASA and involving a wide array of instruments and observation platforms The resulting study of Kohoutek was in its time the most comprehensive and detailed of any comet the scale of the international effort to observe the comet would not be surpassed until the 1986 International Halley Watch for Halley s Comet 23 75 nbsp The crew of Skylab 4 discussing their observations of the comet via television on 28 December 1973 nbsp Skylab 4 emblem Of particular interest were the molecular makeup of the comet and the dust in its tail 68 Many of the observations focused on the possible detection of water which until Kohoutek had been never detected in a comet 23 87 e While the presence of water in comets could be inferred by the identification of hydroxide and hydrogen constituents in previous comets the prominent spectral signature of water in Kohoutek s tail was the first conclusive evidence that comets contained water 89 Observations also aimed to detect complex molecules in the comet before Kohoutek no molecule with more than three atoms had ever been detected in a comet 90 The detection of methyl cyanide in Kohoutek s nucleus was the first time such a molecule had been observed in a comet It was also the first direct evidence of the hypothesis that comet nuclei harbored complex and stable chemical compounds also known as parent molecules that sublimated or dissociated into the chemically unstable radicals and simpler molecules often identified in cometary spectra 58 50 Kohoutek also marked the first time that hydrogen cyanide was identified in a comet 88 supporting the hypothesis that hydrogen cyanide could be a parent molecule of the cyano radical previously detected in comets 91 The signature of silicon in infrared spectra of Kohoutek offered the first direct evidence of silicon in comets 11 The identification of a hydrogen cloud surrounding Kohoutek and its Lyman alpha line signature validated earlier predictions that comets amass hydrogen The low abundance of methane in Kohoutek and what Whipple described as chemically ill mated carbon molecules suggested that comets were formed from the aggregation of compounds at low temperatures as opposed to the cooling of hot gasses possibly pointing to a larger role of the interstellar medium in providing the constituents of cometary compositions 88 Acetone ammonia and helium were not detected in Kohoutek despite searches 60 nbsp In observing Kohoutek Mariner 10 became the first interplanetary spacecraft to observe a comet Skylab the Orbiting Astronomical Observatory the Orbiting Solar Observatory ground observatories and various sounding rockets were among the many observing platforms used to investigate Kohoutek during the comet s approach 90 Some resources in other projects under the auspices of NASA were redirected to study the comet The newly built Joint Observatory for Cometary Research near Socorro New Mexico was made operational in time to observe the comet 16 92 In June 1973 NASA also briefly considered launching a spacecraft to intercept and investigate the comet via either a Thor Delta or Atlas Centaur launch vehicle but scrapped the proposal due to insufficient preparation time 93 94 Skylab 4 the third crewed mission to the Skylab space station was scheduled favorably for the passage and perihelion of Kohoutek 90 As a result a substantial observation program targeting Kohoutek was appended to the original Skylab 4 mission with the launch date selected due to scientific interest in the comet 95 18 12 The observation of the comet from Skylab was primarily conducted using instruments already on the space station along with the backup of the Far Ultraviolet Camera Spectrograph from Apollo 16 Due to Skylab s orbit around Earth the comet could only be observed for at most 26 minutes at a time When Kohoutek appeared closest to the Sun on 27 December 1973 Skylab instruments were trained on the comet almost continuously for 21 consecutive orbits 96 Mariner 10 en route to Venus also made ultraviolet measurements of Kohoutek at a distance of around 0 7 AU in January 1974 55 97 making the comet the first to be observed by an interplanetary spacecraft 64 Although the comet s unexpected faintness prevented clear television images from being obtained by the spacecraft Mariner 10 s ultraviolet spectrometer nonetheless collected useful data concerning Kohoutek s hydrogen coma 98 Pioneer 6 and Pioneer 8 recorded data from within the comet s tail in 1974 99 The results of the observations conducted as part of Operation Kohoutek were presented in June 1974 at a workshop held at the Marshall Space Flight Center 100 Comet science saw considerable advances as a result of the observational research conducted on Kohoutek 75 ushering in what Fred Whipple termed a renaissance of cometary research 22 At the time most scientists accepted Whipple s hypothesis that cometary nuclei were dirty snowballs made mostly of ices However there were other alternative models for comet nuclei such as the sand bank model championed by British astronomer Raymond A Lyttleton which considered nuclei as loose collections of dust particles with negligible amounts of ice 101 3 5 The detection and identification of various gasses emanating from Kohoutek validated the predictions of Whipple s model 89 102 103 Kohoutek s behavior led to the development of more detailed models seeking to explain the physical structure of comet nuclei 47 One proposal suggested that Kohoutek belonged to a subset of comets containing a non volatile dust mantle around an icy volatile core 104 The occultation of the radio source PKS 2025 15 by Kohoutek s tail on 5 January 1974 also served as an opportunity to study interplanetary scintillation 105 106 Media coverage and viewing events edit nbsp Lubos Kohoutek briefing the press on expectations for the comet on 5 January 1974 A hundred years from now how will our great great grandchildren remember 1973 In a future age when the names of Nixon and Brezhnev are dimly remembered and those of Ervin and Mitchell and Dean are minor footnotes in scholarly treatises the name and the discovery that will illuminate the 1973 will be Lubos Kohoutek William Safire Kohoutek s Comet The New York Times 30 July 1973 107 Kohoutek was in its time the most publicized comet aside from Halley s Comet 15 The media attention was brought about by a combination of factors including the early predictions of its brightness its passage concurrent with the Christmas and holiday season the involvement of many observatories and powerful telescopes and the possible effort of a manned spaceflight mission Skylab 4 to investigate the comet 16 108 NASA also pursued an extensive public relations campaign that led to widespread coverage of the comet s approach in American newspapers in the final six months of 1973 16 Dale D Myers the Associate Administrator for Manned Space Flight at NASA commented in July 1973 that comets of Kohoutek s size come this close once in a century further adding to the public interest 16 13 On the 30 July 1973 edition of the New York Times columnist William Safire wrote that Kohoutek may well be the biggest brightest most spectacular astral display that living man has ever seen 107 In August 1973 a reporter from The Mercury News in San Jose California wrote that researchers preparing to study the comet at NASA s Ames Research Center were calling Kohoutek the comet of the century this honorific quickly became associated with the comet NASA s decision to postpone the launch of Skylab 4 to support observations of the comet only further intensified public interest and added to the attention of the press towards Kohoutek after 16 August 1973 Despite more reserved and cautious statements from scientists regarding the comet s luminosity stories referencing the more bullish and earlier estimates of Kohoutek s brightness continued to circulate as the comet drew closer disregarding revised estimates 16 One edition of Time placed the comet on its cover 13 However NASA spokespeople continued to relay an expectation that the comet would be a generational event As November 1973 passed newspapers began to more frequently convey the guarded skepticism that surrounded Kohoutek s brightness Seizing the opportunity created by the comet in giving NASA good publicity an adviser to NASA administrator James C Fletcher proposed a half hour television special featuring the comet Skylab and a Christmas message from the first family of the U S However John Donnelly the NASA Assistant Administrator for Public Affairs derided the proposal because of its intertwining of politics with NASA The proposal continued to be hotly contested within NASA but was eventually dropped Although a spokesman for the Goddard Space Flight Center later stated that Kohoutek was a roaring success for science from a public relations point of view it was a disaster 16 nbsp The Queen Elizabeth 2 pictured in August 1973 sailed on a special three day cruise offering telescope views and comet lectures in December 1973 Queen Elizabeth 2 sailed on a sold out cruise to nowhere dedicated to the comet from 9 12 December 1973 including guest of honor Lubos Kohoutek Isaac Asimov and Kenneth Franklin were also present on the cruise 109 110 Astrophotography discussions and lectures discussing astronomy and the comet led by scientists from Dowling College were also held on board 110 111 Overcast and rainy conditions prevented views of the comet during the trek which departed from New York and remained along the U S East Coast before returning to New York 109 112 113 In his final autobiography Asimov later wrote that even if it hadn t been cloudy and rainy every night Comet Kohoutek proved a colossal disappointment 114 Queen Elizabeth 2 later embarked on similar cruises in the Caribbean in January 1974 which afforded better views of the comet Buzz Aldrin Hugh Downs Burl Ives and Carl Sagan featured on the Caribbean cruises with Hayden Planetarium director Mark Chartrand serving as the cruise s resident astronomer 109 113 The SS Rotterdam departed on a nine day cruise beginning on 3 January 1974 to Puerto Rico and the Virgin Islands that was billed as a Caribbean Comet Watch Cruise educational astronomy segments on the cruise were led by astronomer Lloyd Motz Freelandia flew 149 of its members to Peru to view the comet in December 1973 Another chartered trip sponsored by the Hayden Planetarium to take passengers to observatories to view the comet was canceled 113 The American Automobile Association advised travelers to bring binoculars on roadtrips between December 1973 and February 1974 in anticipation of the comet s apparition 115 Planetariums throughout the U S launched comet centered events and established hotlines offering information regarding Kohoutek 16 The William Miller Sperry Observatory at Union County College and the observatory on the roof of Boyden Hall at Rutgers University Newark both in New Jersey made their facilities accessible to the public interested in the comet with the former maintaining a phone line for updates on the comet 116 Cultural impact edit nbsp Kohoutek s anticipated brightness and apparition around Christmas was a spiritual significance in some religious fundamentalist circles It is among nonpatients that I have seen the most interest in the comet in some instances the impact has already been profound Many Christians have seen an umistakable link between the fact of Kohoutek s December 28 perihelion and the Christmas observance Some individuals have seemed to downplay the signifiance the event has for reasons of propriety or in the interest of appearing sensible A fair number of young adults have taken the comet to be some kind of sign the significance to each individual varying with his specific religious or general spiritual outlook Lawrence Weiner letter to the editor American Journal of Psychiatry March 1974 117 With predictions of Kohoutek s exceptional brightness being well circulated the comet became a cultural and media phenomenon by mid summer 1973 leading to widespread cometary paraphernalia apparel and accessories 76 Sales of telescopes rose sharply leading up to the comet s anticipated appearance Edmund Scientific Corporation reported a 200 percent increase in its sale of telescopes in 1973 relative to 1972 3 2 Sales for telescopes and binoculars quadrupled at Macy s after the company ran a seven column ad in the New York Times Interest in popular astronomy books also increased as the comet neared Pinnacle Books published and quickly sold 750 000 copies of astrologer Joseph Goodavage s book The Comet Kohoutek which described the comet as a harbinger of God 113 118 Astronomers appeared more frequently on television talk shows and were in greater demand as lecturers to speak on comets 113 Carl Sagan appeared on The Tonight Show Starring Johnny Carson to discuss the comet 119 6 The timing of Kohoutek s visible apparition around Christmastide was of spiritual significance to fundamentalist Christians in some circles Kohoutek became known as the Christmas comet It renewed interest in the nature of the Star of Bethlehem including the idea that the event may have been a comet Some fundamentalist Protestants interpreted the comet as a harbinger of the Second Coming Radio preacher Carl McIntire stated that the comet was so beyond anything men have ever seen before and that only the Holy Scripture offered anything to explain it 120 Kohoutek also took on spiritual significance in the New Age movement and other followers of Western esotericism 13 One view was that the comet heralded a new cosmic age the age of Kohoutek Proponents of this view organized the Kohoutek Celebration of Consciousness at the Bill Graham Civic Auditorium in San Francisco in January 1974 121 For some the comet s arrival was a portent of disaster 122 In 1973 David Berg founder of the Children of God predicted that Comet Kohoutek foretold a colossal doomsday event in the United States by the end of January 1974 because of divine judgment and America s wickedness Some of the movement s followers intended to leave the U S in response to the impending comet 120 There were other circulated fringe claims predicting that the comet would cause mass hysteria or spell death for humanity by igniting the global oil supply 3 2 Because Kohoutek fell far short of expectations its name became synonymous with spectacular disappointment 123 124 199 Russell Baker described the comet as the biggest flopperoo since Kelly hit Broadway and the Edsel of the firmament among other witty metaphors 125 While newspapers had been touting the comet s brightness for the latter half of 1973 the anticlimactic display led to satirical and parodical reporting following Kohoutek s passage For instance the Chicago Tribune featured a satirical article linking the optimistic brightness predictions to an effort to distract the public from the Watergate scandal or to a conspiracy to boost telescope sales 16 The widely circulated inaccurate projections came during a time of increasing distrust of the sciences that Time termed a deepening disillusionment 126 Mainstream media shied away from extensive coverage of comets following Kohoutek despite Comet West becoming bright enough to be visible in daylight in March 1976 West received little attention from the press compared to the media frenzy that preceded Kohoutek 76 Though astronomers and the sciences received backlash due to the comet s underwhelming performance much of the general public s disdain was also directed towards astrologers and cultists who ascribed a transcendental significance to the comet s apparition 118 In response to the disappointing display from the comet students at Pitzer College organized the Kohoutek Music and Arts Festival in January 1974 127 which became an annual event featuring various musical artists 128 Several music albums and songs released in the 1970s and 1980s were dedicated to or named after Kohoutek such as Kohoutek from Journey s eponymous debut album released in 1975 129 130 Sun Ra played a concert at The Town Hall in New York dedicated to Kohoutek s arrival on 22 December 1973 131 Other musical groups with works influenced by the comet included Kraftwerk Pink Floyd Argent R E M and Weather Report Girl 119 7 References to Kohoutek permeated other forms of popular media such as in the comic strip Peanuts over a week long period 119 7 in the sitcom El Chavo del Ocho and a poem by Jaime Sabines 132 In The Defenders 15 September 1974 the Comet Kohoutek is mentioned as having freed Magneto from imprisonment within the Earth s core 133 See also editComet ISON sungrazing comet that disintegrated upon passing close to the Sun C 1989 X1 Austin fell short of brightness predictions in spring 1990 Comet Ikeya Seki one of the brightest comets on record Oort cloud Interstellar objectNotes edit A teaching guide published by the Educational Programs Branch of the NASA Goddard Space Flight Center lists the pronunciation of Kohoutek as KŌ HU TEK 1 iii A January 1974 article in the New York Times provided the phonetic pronunciation ko ho tek without any accented syllables 2 A special report on the comet in Time gave the phonetic pronunciation ko hoe tek 3 1 Most comets have an albedo of around 0 04 The designation C 1973 E1 reflects the modern comet designation scheme adopted by the International Astronomical Union in 1995 and indicates that Comet Kohoutek appeared once and was the first comet discovered in the first half of March 1973 However during the time of perihelion the comet was contemporaneously designated as 1973f as it was sixth comet discovered in 1973 or alternatively as 1973 XII as the comet was the twelfth to reach perihelion in 1973 9 10 1 3 All mentions of apparent magnitude in this article refer to brightness in visible light unless otherwise noted a b Observations identified the cation of water H2 O in Kohoutek It would not be until Comet Bradfield 1974 III that neutral water H2 O was detected in a comet 88 1971 UG is a main belt asteroid about 10 km in diameter discovered by Kohoutek on 26 October 1971 20 It is also known as 1980 RT3 and 1995 UZ44 It has been observed every year since 1998 The first comet discovered by Kohoutek in 1973 was designated 1973e modern designation C 1973 D1 and has an orbital period of about 36 751 years It reached its perihelion on 7 June 1973 and was last observed in October 1973 21 15 References edit a b c d e Chapman Robert D September 1973 Comet Kohoutek A Teacher s Guide With Student Activities PDF Technical Memorandum Greenbelt Maryland NASA Archived PDF from the original on 6 July 2022 Retrieved 6 July 2022 McElheny Victor 7 January 1974 Discoverer of Comet Lubas Kohoutek The New York Times New York p 61 Archived from the original on 6 July 2022 Retrieved 6 July 2022 a b c d e SPECIAL REPORT Kohoutek Comet of the Century Time Vol 102 no 25 17 December 1973 Archived from the original on 8 July 2022 Retrieved 8 July 2022 a b c d e f g JPL Horizons Orbital Elements at epoch 1600 and 2500 JPL Horizons On Line Ephemeris System Jet Propulsion Laboratory Archived from the original on 3 August 2022 Retrieved 3 August 2022 Solution using the Solar System Barycenter Ephemeris Type Elements and Center 0 To be outside planetary region inbound epoch 1600 and outbound epoch 2500 Aphelia orbital periods defined while in the planetary region are misleading for knowing the long term inbound outbound solutions a b c d C 1973 E1 Kohoutek Minor Planet Center Archived from the original on 20 September 2022 Retrieved 7 July 2022 a b c d C 1973 E1 Kohoutek Small Body Database Lookup Jet Propulsion Laboratory Archived from the original on 7 February 2022 Retrieved 7 July 2022 a b c d e f g O Dell C R June 1976 Physical processes in Comet Kohoutek Publications of the Astronomical Society of the Pacific 88 523 342 348 Bibcode 1976PASP 88 342O doi 10 1086 129954 JSTOR 40675895 S2CID 120855634 Brightest comets seen since 1935 International Comet Quarterly Archived from the original on 18 September 2013 Retrieved 8 July 2022 Comet Names and Designations Comet Naming and Nomenclature Names of Comets International Comet Quarterly Archived from the original on 29 July 2012 Retrieved 7 July 2022 a b c d Green Daniel W E Marsden Brian G Morris Charles S February 2001 Brightness predictions for comets Astronomy and Geophysics 42 1 1 11 1 12 Bibcode 2001A amp G 42a 11G doi 10 1046 j 1468 4004 2001 0420011 11 x S2CID 12022471 a b c d e f g h i j k l m n o p Hendrie Michael J February 2000 Comet Kohoutek 1973f Journal of the British Astronomical Association 110 9 19 Bibcode 2000JBAA 110 9H a b c d e f Kohoutek Lubos December 1974 On the discovery of Comet Kohoutek 1973f Icarus 23 4 491 492 Bibcode 1974Icar 23 491K doi 10 1016 0019 1035 74 90011 6 S2CID 120800003 a b c d e f g h i j k Stoyan Ronald 2015 Comet Kohoutek 1973 74 Atlas of Great Comets English ed Cambridge United Kingdom Cambridge University Press pp 166 169 ISBN 9781316195727 Archived from the original on 20 September 2022 Retrieved 6 July 2022 via Google Books a b c d e f Biermann L December 1973 Comet Kohoutek Nature 246 5433 400 402 Bibcode 1973Natur 246 400B doi 10 1038 246400a0 S2CID 42320124 a b c d e f g h i j Marsden Brian G December 1974 Comets in 1973 Quarterly Journal of the Royal Astronomical Society 15 433 460 Bibcode 1974QJRAS 15 433M a b c d e f g h i j Benson Charles Dunlap Compton William David Appendix F Comet Kohoutek Living and Working in Space A History of Skylab Washington D C NASA Archived from the original on 28 August 2021 Retrieved 14 July 2022 Roemer Elizabeth 1976 Luminosity and Astrometry of Comets A Review PDF The Study of Comets Part 1 393 NASA 380 409 Bibcode 1976NASSP 393 380R Archived PDF from the original on 26 May 2022 Retrieved 9 July 2022 a b c MSFC Skylab Kohoutek Project Report PDF NASA Technical Memorandum Huntsville Alabama NASA Marshall Space Flight Center October 1974 NASA TM X 64880 Archived PDF from the original on 20 September 2022 Retrieved 8 July 2022 a b c d e f g h i j Whipple Fred L 5 February 1976 Comet Kohoutek in Retrospect Proceedings of the American Philosophical Society 120 1 1 6 Bibcode 1976PAPhS 120 1W JSTOR 986346 S2CID 236815067 MPC object 8606 Archived from the original on 4 March 2016 Retrieved 5 August 2022 C 1973 D1 Kohoutek Small Body Database Lookup Jet Propulsion Laboratory Archived from the original on 7 February 2022 Retrieved 4 September 2022 a b c d e f Whipple F L June 1989 Comets in the space age The Astrophysical Journal 341 1 13 Bibcode 1989ApJ 341 1W doi 10 1086 167466 S2CID 121228906 a b c d Dubin Maurice 1975 Foreword In Gary Gilmer ed Comet Kohoutek A Workshop Held at Marshall Space Flight Center Vol 355 Washington D C NASA Bibcode 1975NASSP 355 G a href Template Cite book html title Template Cite book cite book a journal ignored help a b The Christmas Comet Begins Yielding Data Science News 104 17 262 27 October 1973 doi 10 2307 3958219 JSTOR 3958219 a b Lyttleton R A September 1973 Prospects for Comet Kohoutek 1973f Nature 245 5422 200 201 Bibcode 1973Natur 245 200L doi 10 1038 245200a0 S2CID 4255566 Stokley James 22 December 1973 Kohoutek Comet Now Visible Science News 104 25 26 400 doi 10 2307 3958267 JSTOR 3958267 S2CID 86901151 Horizons output Osculating Orbital Elements for Comet C 1973 E1 Kohoutek a b Fulle M July 1988 Meteoroids from comet Kohoutek 1973 XII Astronomy and Astrophysics 201 1 161 168 Bibcode 1988A amp A 201 161F S2CID 116263177 a b Horizons Batch for Heliocentric distance for 2022 2030 JPL Horizons Archived from the original on 4 August 2022 Retrieved 3 August 2022 Ney Edward P December 1974 Multiband photometry of Comets Kohoutek Bennett Bradfield and Encke Icarus 23 4 551 560 Bibcode 1974Icar 23 551N doi 10 1016 0019 1035 74 90018 9 S2CID 121046622 Chaisson E J Ingalls R P Rogers A E E Shapiro I I February 1975 Upper limit on the radar cross section of the comet Kohoutek Icarus 24 2 188 189 Bibcode 1975Icar 24 188C doi 10 1016 0019 1035 75 90096 2 S2CID 119908758 a b Jockers K December 1985 The ion tail of Comet Kohoutek 1973 XII during 17 days of solar wind gusts Astronomy and Astrophysics Supplement Series 62 4 791 838 Bibcode 1985A amp AS 62 791J S2CID 120216058 Jambor B J 1975 Dynamical and Colorimetric Study of the Dust Tail of Comet Kohoutek In Gary Gilmer ed Comet Kohoutek A Workshop Held at Marshall Space Flight Center Vol 355 Washington D C NASA pp 209 216 Bibcode 1975NASSP 355 209J a href Template Cite book html title Template Cite book cite book a journal ignored help Brandt John C 1975 Large Scale Observations of the Ion Tail from the Joint Observatory for Cometary Research In Gary Gilmer ed Comet Kohoutek A Workshop Held at Marshall Space Flight Center Vol 355 Washington D C NASA pp 15 18 Bibcode 1975NASSP 355 15B a href Template Cite book html title Template Cite book cite book a journal ignored help Wright C S Nelson G J April 1979 Comet plasma densities deduced from refraction of occulted radio sources Icarus 38 1 123 135 Bibcode 1979Icar 38 123W doi 10 1016 0019 1035 79 90092 7 S2CID 122229848 Ershkovich A I March 1976 Solar wind interaction with the tail of Comet Kohoutek Planetary and Space Science 24 3 287 291 Bibcode 1976P amp SS 24 287E doi 10 1016 0032 0633 76 90025 8 S2CID 121782993 a b c de Almeida A A April 1996 Photoelectric photometry of comet Kohoutek 1973 XII C 1973 E1 the production rates of CN C2 and solid refractory particles typical of dynamically new comets Planetary and Space Science 44 4 295 304 Bibcode 1996P amp SS 44 295D doi 10 1016 0032 0633 95 00130 1 S2CID 123609347 Lisse C M A Hearn M F Hauser M G Kelsall T Lien D J Moseley S H Reach W T Silverberg R F April 1998 Infrared Observations of Comets by COBE The Astrophysical Journal 496 2 971 991 Bibcode 1998ApJ 496 971L doi 10 1086 305397 S2CID 119698136 Ney Edward P May 1974 Infrared Observations of Comet Kohoutek Near Perihelion The Astrophysical Journal 189 L141 L142 Bibcode 1974ApJ 189L 141N doi 10 1086 181486 S2CID 120737009 Sekanina Zdenek Miller Freeman D January 1976 On the nature of the anti tail of Comet Kohoutek 1973f II Comparison of the working model with ground based photographic observations Icarus 27 1 135 146 Bibcode 1976Icar 27 135S doi 10 1016 0019 1035 76 90190 1 hdl 2027 42 21881 S2CID 56252570 a b A Hearn Michael F Cowan J J October 1975 Molecular production rates in Comet Kohoutek The Astronomical Journal 80 852 Bibcode 1975AJ 80 852A doi 10 1086 111821 S2CID 121989799 Gatley I Becklin E E Neugebauer G Werner M W December 1974 Infrared observations of Comet Kohoutek 1973f Icarus 23 4 561 565 Bibcode 1974Icar 23 561G doi 10 1016 0019 1035 74 90019 0 S2CID 121839693 A Hearn Michael F October 1975 Spectrophotometry of comet Kohoutek 1973f 1973 XII Astronomical Journal 80 10 861 875 Bibcode 1975AJ 80 861A doi 10 1086 111822 S2CID 123614672 Hoffmann H J Fechtig H Grun E Kissel J 1976 Particles from Comet Kohoutek Detected by the Micrometeoroid Experiment on HEOS 2 International Astronomical Union Colloquium 25 2 949 961 Bibcode 1976NASSP 393 949H doi 10 1017 S0252921100034357 hdl 2060 19760014003 S2CID 118057535 Grun E Kissel J Hoffmann H J 1976 Dust emission from Comet Kohoutek 1973f at large distances from the sun Interplanetary Dust and Zodiacal Light Lecture Notes in Physics Vol 48 pp 334 338 Bibcode 1976LNP 48 334G doi 10 1007 3 540 07615 8 503 ISBN 978 3 540 07615 5 S2CID 118694750 Rieke G H Lee T A April 1974 Photometry of Comet Kohoutek 1973f Nature 248 5451 737 740 Bibcode 1974Natur 248 737R doi 10 1038 248737a0 S2CID 4281170 a b Huebner W F 1975 On the structure of the nucleus of comet Kohoutek 1973f In Gary Gilmer ed Comet Kohoutek A Workshop Held at Marshall Space Flight Center Vol 355 Washington D C NASA pp 145 152 Bibcode 1975NASSP 355 15B a href Template Cite book html title Template Cite book cite book a journal ignored help Herzberg G Lew H February 1974 Tentative Identification of the H2 O Ion in Comet Kohoutek Astronomy and Astrophysics 31 123 124 Bibcode 1974A amp A 31 123H doi 10 1017 S0252921100500864 S2CID 125675140 Wehinger Peter Wyckoff Susan 1976 H20 Ions in Comets Comet Kohoutek 1973f and Comet Bradfield 1974b International Astronomical Union Colloquium 25 Part1 199 205 doi 10 1017 S0252921100500864 a b Mendis D A Ip W H June 1974 Behaviour of Comet Kohoutek 1973f Nature 249 5457 536 537 Bibcode 1974Natur 249 536M doi 10 1038 249536a0 S2CID 4297924 Herbig George 1975 Spectroscopy of the Coma and Tail In Gary Gilmer ed Comet Kohoutek A Workshop Held at Marshall Space Flight Center Washington D C NASA pp 233 235 Feldman Paul D Takacs Peter Z Fastie William G Donn Bertram 23 August 1974 Rocket Ultraviolet Spectrophotometry of Comet Kohoutek 1973f Science 185 4152 705 707 Bibcode 1974Sci 185 705F doi 10 1126 science 185 4152 705 JSTOR 1738738 PMID 17736378 S2CID 43534328 a b Opal C B Carruthers G R Prinz D K Meier R R 23 August 1974 Comet Kohoutek Ultraviolet Images and Spectrograms Science 185 4152 702 705 Bibcode 1974Sci 185 702O doi 10 1126 science 185 4152 702 JSTOR 1738737 PMID 17736377 S2CID 45497893 a b Huppler D Reynolds R J Roesler F L Scherb F Trauger J November 1975 Observations of comet Kohoutek 1973f with a ground based Fabry Perot spectrometer The Astrophysical Journal 202 276 282 Bibcode 1975ApJ 202 276H doi 10 1086 153974 S2CID 120798083 a b Kumar S Holberg J Broadfoot A L Belton M J S September 1979 The Lyman alpha observations of comet Kohoutek from Mariner 10 The Astrophysical Journal 232 616 Bibcode 1979ApJ 232 616K doi 10 1086 157320 S2CID 120955159 Marsden Brian G 1979 Comet Halley and history NASA Goddard Space Flight Center Space Missions to Comets 2089 179 196 Bibcode 1979NASCP2089 179M Feldman Paul D 28 January 1983 Ultraviolet Spectroscopy and the Composition of Cometary Ice Science 219 4583 347 354 Bibcode 1983Sci 219 347F doi 10 1126 science 219 4583 347 JSTOR 1689912 PMID 17815301 S2CID 37048944 a b Ulich B L Conklin E K March 1974 Detection of methyl cyanide in Comet Kohoutek Nature 248 5444 121 122 Bibcode 1974Natur 248 121U doi 10 1038 248121a0 S2CID 4287565 Huebner W F Snyder L E Buhl D December 1974 HCN radio emission from Comet Kohoutek 1973f Icarus 23 4 580 584 Bibcode 1974Icar 23 580H doi 10 1016 0019 1035 74 90023 2 S2CID 123086883 a b Whipple Fred L 1977 Comets Data problems and objectives PDF The Soviet American Conference on Cosmochemistry of the Moon and Planets 370 923 929 Bibcode 1977NASSP 370 923W Archived PDF from the original on 10 July 2022 Retrieved 10 July 2022 Delsemme A H Combi M R August 1983 Neutral cometary atmospheres IV Brightness profiles in the inner coma of comet Kohoutek 1973 XII The Astrophysical Journal 271 388 397 Bibcode 1983ApJ 271 388D doi 10 1086 161204 S2CID 120962101 a b c d Goraya P S Rautela B S Sanwal B B January 1986 Absolute spectrophotometry of Comet kohoutek 1973f during post perihelion passage Earth Moon and Planets 34 1 77 91 Bibcode 1986EM amp P 34 77G doi 10 1007 BF00054037 S2CID 120188816 Wyckoff S Wehinger P A March 1976 Molecular ions in comet tails The Astrophysical Journal 204 604 Bibcode 1976ApJ 204 604W doi 10 1086 154209 S2CID 120955304 a b c d e Hale Alan 27 December 2020 Comet of the Week Kohoutek 1973f RocketSTEM Archived from the original on 10 July 2022 Retrieved 10 July 2022 Bennett J C December 1973 Visual observations of Comet Kohoutek 1973f Monthly Notes of the Astronomical Society of Southern Africa 32 10 11 12 107 108 Bibcode 1973MNSSA 32 107B doi 10 1038 246400a0 S2CID 42320124 a b Ferrin Ignacio 1 August 2014 The location of Oort Cloud comets C 2011 L4 Panstarrs and C 2012 S1 ISON on a comet evolutionary diagram Monthly Notices of the Royal Astronomical Society 442 2 1731 1754 arXiv 1306 5010 Bibcode 2014MNRAS 442 1731F doi 10 1093 mnras stu820 S2CID 54846398 Gibson Edward G December 1974 Visual observations of Comet Kohoutek from Skylab III Icarus 23 4 493 501 Bibcode 1974Icar 23 493G doi 10 1016 0019 1035 74 90012 8 S2CID 122741070 a b c James J F April 1975 What came out of Kohoutek s comet Nature 254 5499 382 383 Bibcode 1975Natur 254 382J doi 10 1038 254382b0 S2CID 4163458 Skylab 1 4 Technical Air to Ground Voice Transcription Houston Texas NASA November 1973 Kidger Mark R 1994 The frequency of appearance of bright naked eye comets since 1750 Are bright comets less frequent in the 20th Century Earth Moon and Planets 66 2 231 238 Bibcode 1994EM amp P 66 231K doi 10 1007 BF00644134 S2CID 119875072 Marsden Brian G Roemer Elizabeth March 1978 Comets in 1974 Quarterly Journal of the Royal Astronomical Society 19 38 58 Bibcode 1978QJRAS 19 38M Hyder Charles L Brandt John C Roosen Robert G December 1974 Tail structure far from the head of Comet Kohoutek Icarus 23 4 601 610 Bibcode 1974Icar 23 601H doi 10 1016 0019 1035 74 90028 1 S2CID 119997643 Terenteva A K Kruchinenko V G Triashin S S July 1976 Observations of meteors connected with comet Kohoutek 1973f Astronomicheskii Vestnik 10 1 70 71 Bibcode 1976AVest 10 70T a b Eberhart Jonathan 4 May 1974 Eyes on the Comet Science News 105 18 290 291 doi 10 2307 3958991 JSTOR 3958991 S2CID 87707864 a b c d Murdin Paul ed November 2000 Computer Kohoutek C 1973 E1 Encyclopedia of Astronomy amp Astrophysics First ed Boca Raton Florida CRC Press p 771 Bibcode 2000eaa bookE5239 doi 10 1888 0333750888 5239 ISBN 9781000523034 a b c d Rao Joe 22 January 2020 How the comet of the century became an astronomical disappointment Space com Archived from the original on 8 April 2022 Retrieved 9 July 2022 a b Huge comet at Christmas to be visible The Montreal Star No 81 Montreal Quebec 5 April 1973 p 13 Archived from the original on 20 September 2022 Retrieved 6 July 2022 via Newspapers com nbsp New comet holds brilliant hope for star gazers The Morning News Vol 183 no 83 United Press International 6 April 1973 p 10 Archived from the original on 20 September 2022 Retrieved 9 July 2022 via Newspapers com nbsp Avery Lorne October 1973 Orbital Data for Comet Kohoutek 1973f Journal of the Royal Astronomical Society of Canada Newsletter 67 L25 L26 Bibcode 1973JRASC 67L 25A Kohoutek Predictions Toned Down Sentinel Star No 315 Associated Press 11 November 1973 p 22C Archived from the original on 20 September 2022 Retrieved 10 July 2022 via Newspapers com nbsp Sullivan Walter 17 January 1974 Observations of Kohoutek Appear to Confirm Concept of Comets as snowballs The New York Times New York p 24 Archived from the original on 15 July 2022 Retrieved 15 July 2022 Angione Ronald J Gates Bill Henize Karl G Roosen Robert G January 1975 The light curve of comet Kohoutek Icarus 24 1 111 115 Bibcode 1975Icar 24 111A doi 10 1016 0019 1035 75 90164 5 S2CID 119799157 Opik E J September 1977 On Predicting the Brightness of Comets Irish Astronomical Journal 13 3 4 92 94 Bibcode 1977IrAJ 13 92O Sekanina Zdenek 1976 A Continuing Controversy Has the Cometary Nucleus been Resolved International Astronomical Union Colloquium 25 2 537 587 doi 10 1017 S0252921100034084 hdl 2060 19760013988 Whipple Fred L 1975 Implications for Models and Origin of the Nucleus In Gary Gilmer ed Comet Kohoutek A Workshop Held at Marshall Space Flight Center Washington D C NASA pp 227 232 Whipple Fred L 1985 Present Status of the Icy Conglomerate Model In Klinger Jurgen Benest Daniel Dollfus Audouin Smoluchowski Roman eds ICES in the Solar System Mathematical and Physical Sciences Volume 156 D Reidel Publishing Company pp 343 366 doi 10 1007 978 94 009 5418 2 23 ISBN 9789401088916 Ip W H Mendis D A September 1973 Development of an H2 O Atmosphere around Comet Kohoutek 1973f and its Possible Detection Nature 245 5422 197 199 Bibcode 1973Natur 245 197I doi 10 1038 245197a0 S2CID 4245004 a b c Whipple Fred L September 1976 Background of modern comet theory Nature 263 5572 15 19 Bibcode 1976Natur 263 15W doi 10 1038 263015a0 S2CID 40079180 a b Wehinger P A Wyckoff S Herbig G H Herzberg G Lew H May 1974 Identification of H2 O in the Tail of Comet Kohoutek 1973f The Astrophysical Journal 190 L43 Bibcode 1974ApJ 190L 43W doi 10 1086 181500 S2CID 121346176 a b c Metz William D 27 July 1973 Kohoutek the Christmas Comet Skylab Mission Expanded Science 181 4097 333 334 Bibcode 1973Sci 181 333M doi 10 1126 science 181 4097 333 JSTOR 1736609 PMID 17832027 S2CID 31602518 Krankowsky Dieter 1991 Section V The Cometary Coma The Composition of Comets Vol 116 Cambridge University Press pp 854 877 Bibcode 1991ASSL 167 855K doi 10 1017 S0252921100012744 a href Template Cite book html title Template Cite book cite book a journal ignored help Brandt John C 1 October 1981 The JOCR Program PDF JPL Mod Observational Tech for Comets Report NASA pp 171 184 Archived PDF from the original on 15 July 2022 Retrieved 15 July 2022 June Astronautics and Aeronautics 1973 Chronology of Science Technology and Policy Washington D C NASA 1975 p 191 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Sullivan Walter 16 June 1973 Plan to Intercept Comet For Close Study Weighed The New York Times New York p 56 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Skylab 3 to study a brilliant comet The New York Times Associated Press 17 August 1973 p 18 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Lundquist Charles A ed 4 Observations of Comet Kohoutek Skylab s Astronomy and Space Sciences Washington D C NASA Archived from the original on 13 November 2004 Retrieved 9 July 2022 Mars Kelli ed 5 February 2019 45 Years Ago Mariner 10 flies by Venus NASA History NASA Archived from the original on 10 July 2022 Retrieved 8 July 2022 Dunne James A Burgess Eric 1978 5 Venus Bound Success and Near Failure The Voyage of Mariner 10 Washington D C NASA Archived from the original on 24 January 2021 Retrieved 14 July 2022 Pioneer 06 Solar System Exploration NASA 11 August 2019 Archived from the original on 12 July 2022 Retrieved 14 July 2022 Roemer E 18 June 1976 Operation Kohoutek Science 192 4245 1227 Bibcode 1976Sci 192 1227R doi 10 1126 science 192 4245 1227 JSTOR 1742598 PMID 17771755 S2CID 34080360 Sullivan Walter 24 December 1973 Revised Theory on Comets Offered The New York Times New York p 30 Archived from the original on 8 July 2022 Retrieved 8 July 2022 Reports in Brief South African Journal of Science 71 December 1975 Archived from the original on 20 September 2022 Retrieved 8 July 2022 Brim Nancy L 1977 Astronautics and Aeronautics 1974 Technical report NASA History Series NASA Bibcode 1977NASSP4019 B NASA SP 4019 Mendis D A Brin G D December 1977 Monochromatic brightness variations of comets II Core Mantle Model The Moon 17 4 359 372 Bibcode 1977Moon 17 359M doi 10 1007 BF00562645 S2CID 119797846 Iju Tomoya Abe Shinsuke Tokumaru Munetoshi Fujiki Ken ichi May 2015 Plasma distribution of Comet ISON C 2012 S1 observed using the radio scintillation method Icarus 252 301 310 arXiv 1410 2119 Bibcode 2015Icar 252 301I doi 10 1016 j icarus 2015 02 007 S2CID 118607736 Lee L C November 1976 Plasma irregularities in the comet s tail The Astrophysical Journal 210 254 257 Bibcode 1976ApJ 210 254L doi 10 1086 154825 hdl 2060 19760012963 S2CID 120556703 a b Safire William 30 July 1973 Kohoutek s Comet The New York Times New York p 27 Archived from the original on 7 July 2022 Retrieved 7 July 2022 Stern Jane Stern Michael 1992 Kohoutek Jane amp Michael Stern s Encyclopedia of Pop Culture An A to Z Guide of Who s who and What s What from Aerobics and Bubble Gum to Valley of the Dolls and Moon Unit Zappa 1st ed New York HarperPerennial pp 266 268 ISBN 9780060553432 a b c Warwick Ronald W 1999 Trafalgar House Cunard and the QE2 QE2 The Cunard Line Flagship Queen Elizabeth II 3rd ed New York W W Norton amp Co p 97 ISBN 9780393047721 a b Segal Jonathan 4 November 1973 Science Cruises Becoming Popular The New York Times New York p 624 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Barney Lillian 2 December 1973 Comet of Century to Get Dim Showing Over L I The New York Times New York p 164 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Schuman Wendy 16 December 1973 Star Fails to Show For QE2 Gazers The New York Times New York p 137 Archived from the original on 14 July 2022 Retrieved 14 July 2022 a b c d e Carlinsky Dan 26 December 1973 Business Boomlet Trailing Kohoutek The New York Times p 65 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Asimov Isaac 1995 Cruises I Asimov A Memoir Bantam pbk ed New York Bantam p 365 ISBN 9780553569971 Travel Notes Survey Of Restrictions on Driving in Europe The New York Times New York 9 December 1973 p 594 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Colleges Aid Comet Watchers The New York Times New York 16 December 1973 Archived from the original on 14 July 2022 Retrieved 14 July 2022 Weiner Lawrence March 1974 On the Comet Kohoutek American Journal of Psychiatry 131 3 331 c 332 doi 10 1176 ajp 131 3 331 c PMC 4812706 PMID 26951657 a b Perlman David 1974 Science and the Mas Media Daedalus 103 3 207 222 JSTOR 20024229 a b c Eicher David J 2013 Comets Visitors from Deep Space New York Cambridge University Press ISBN 9781107513501 a b Fiske Edward B 24 December 1973 Fundamentalists View Christmas Comet as a Sign The New York Times New York Archived from the original on 14 July 2022 Retrieved 14 July 2022 Welcoming the age of Kohoutek San Francisco Examiner Vol 1974 no 4 27 January 1974 p 3 Archived from the original on 20 September 2022 Retrieved 15 July 2022 via Newspapers com nbsp Hoopes John W January 2011 A critical history of 2012 mythology Proceedings of the International Astronomical Union 7 S278 240 248 Bibcode 2011IAUS 278 240H doi 10 1017 S174392131101266X S2CID 194041975 MacPherson Les 4 January 2013 Comet s arrival may be a flop Regina Leader Post Regina Saskatchewan Archived from the original on 14 July 2022 Retrieved 14 July 2022 Evans Ben 2012 At Home in Space The Late Seventies into the Eighties New York Springer Science Business Media LLC ISBN 9781441988102 Baker Russell 15 January 1974 The Cosmic Flopperoo The New York Times New York p 37 Archived from the original on 15 July 2022 Retrieved 15 July 2022 Carroll Peter N 1990 To Heal the Fragmentations Redefining Authority at Mid Decade It Seemed Like Nothing Happened America in the 1970s New Brunswick New Jersey Rutgers University Press pp 13 14 ISBN 9780813515380 Greenberg Annie Kohoutek Planning Commences PDF The Other Side Vol 14 no 2 Claremont California pp 1 3 Archived PDF from the original on 20 September 2022 Retrieved 15 July 2022 Rojas Luca 30 April 2010 Kohoutek Music Festival Goes Big with GZA The Student Life Archived from the original on 27 July 2021 Retrieved 15 July 2022 Bainbridge William Sins 2015 The Impact of Space Exploration on Public Opinions Attitudes and Beliefs In Dick Steven J ed Historical Studies in the Societal Impact of Spaceflight PDF Washington D C NASA p 21 Archived PDF from the original on 1 October 2020 Retrieved 15 July 2022 Karam P Andrew 2017 Comets nature and culture London Reaktion Books ISBN 9781780238586 Hegarty Paul Halliwell Martin 2011 Progressive Fusion Beyond and Before Progressive Rock Since the 1960s New York Bloomsbury Publishing p 115 ISBN 9780826423320 Madrid Alejandro L 2015 Experimentalism Mythology In Search of Julian Carrillo and Sonido 13 New York Oxford University Press p 223 ISBN 9780190215781 The Defenders 15 September 1974 Marvel ComicsExternal links editC 1973 E1 at the JPL Small Body Database nbsp Close approach Discovery Ephemeris Orbit diagram Orbital elements Physical parameters nbsp Wikimedia Commons has media related to Comet Kohoutek Portals nbsp Astronomy nbsp Stars nbsp Spaceflight nbsp Outer space nbsp Solar System Retrieved from https en wikipedia org w index php title Comet Kohoutek amp oldid 1219845963, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.