2011 UW158 orbits the Sun at a distance of 1.0–2.2 AU once every 2 years and 1 month (753 days). Its orbit has an eccentricity of 0.38 and an inclination of 5° with respect to the ecliptic.[1] Its observation arc begins with its official discovery observation by Pan-STARRS, as no precoveries were taken, and no prior identifications were made.[2]
Close approachedit
The asteroid has an Earth minimum orbit intersection distance of 0.0020 AU (300,000 km), which corresponds to 0.8 lunar distances (LD). On 19 July 2015, it passed about 2.5 million kilometers from Earth (6.5 LD),[1] attracting the interest of astronomers.[1] The asteroid was listed as level 1 in the Torino Scale on 4 November 2011, 9 days after its discovery, but was removed two weeks later.[9][10]
Left: Inner solar system orbits; right: Motion of 2011 UW158 across sky, 6 hour motion
Physical characteristicsedit
Spectral typeedit
2011 UW158 is an assumed stony S-type asteroid, the most common type among the populations of near-Earth and inner main-belt asteroids.[5]
Diameter and albedoedit
Bruce Gary at Hereford Arizona Observatory (G95) estimated a mean-diameter of 220 meters with a high albedo of 0.39,[3] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroid of 0.20 and calculates a mean-diameter of 311 meters based on an absolute magnitude of 19.9.[5]
Fast rotatoredit
In July and August 2015, rotational lightcurves of this asteroid were obtained from photometric observations by Bruce Gary at Hereford Arizona Observatory and by Brian Warner at the CS3–Palmer Divide Station in California (U82). Lightcurve analysis gave a rotation period of 0.6107 hours (36.6 minutes) with a brightness variation between 0.52 and 2.05 magnitude (U=3/3/3).[3][6][a] This makes 2011 UW158 one of the Top 200 fast rotator, suggesting it is a large boulder rather than a rubble pile.[6][11]
Shapeedit
Radar observations by the Arecibo Observatory on 14 July 2015, revealed that the asteroid's shape looks like an unshelled walnut with a diameter of 300 by 600 metres. The radiometric observations also agreed with the previously obtained photometric ones and gave a period of 37 minutes.[4][11]
Media attentionedit
It also attracted the media and even firms such as Planetary Resources[12] for its alleged content of platinum worth as high as 5 trillion U.S. dollars.[13][14][15] Commenters at StackExchange have denied these estimations as being "orders of magnitude too high",[16] and radar observations have shown that the object contains no more metal than an average rocky asteroid.[17][18]
Notesedit
^ abLightcurve plot of 2011 UW158 by Brian Warner at the CS3–Palmer Divide Station in July 2015: rotation period of 0.61069±0.00002 hours with an amplitude of 0.65 magnitude
Referencesedit
^ abcdefg"JPL Small-Body Database Browser: 436724 (2011 UW158)" (2017-04-19 last obs.). Jet Propulsion Laboratory. Retrieved 2 June 2017.
^ abc"436724 (2011 UW158)". Minor Planet Center. Retrieved 28 March 2017.
^ abcdefGary, Bruce L. (January 2016). "Unusual Properties for the NEA (436724) 2011 UW158". The Minor Planet Bulletin. 43 (1): 33–38. Bibcode:2016MPBu...43...33G. ISSN 1052-8091. Retrieved 28 March 2017.
^ ab"Solar System Studies at Arecibo Observatory". Arecibo Observatory. Retrieved 23 July 2015.
^ abcdefg"LCDB Data for (436724)". Asteroid Lightcurve Database (LCDB). Retrieved 28 March 2017.
^ abcWarner, Brian D. (January 2016). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 June-September". The Minor Planet Bulletin. 43 (1): 66–79. Bibcode:2016MPBu...43...66W. ISSN 1052-8091. PMC7244002. PMID 32455369. Retrieved 28 March 2017.
^Carbognani, Albino; Gary, Bruce L.; Oey, Julian; Baj, Giorgio; Bacci, Paolo (January 2016). "Pole and Shape for the NEA (436724) 2011 UW158". The Minor Planet Bulletin. 43 (1): 38–41. Bibcode:2016MPBu...43...38C. ISSN 1052-8091. Retrieved 28 March 2017.
^Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID 53493339. Retrieved 28 March 2017.
^. Near Earth Object Program. NASA. Archived from the original on 6 November 2011.
^. Near Earth Object Program. NASA. Archived from the original on 2 June 2002. Retrieved 28 March 2017.
^ ab"First detailed images of rare asteroid to pass close by Earth on 19 July". Astronomy Now. 19 July 2015. Retrieved 28 March 2017.
^"Mining Firm Aiming For Platinum-Loaded Asteroid". Retrieved 23 July 2015.[dead link]
^"UW-158: Watch live as asteroid worth £ 3 TRILLION passes close to Earth". Retrieved 23 July 2015.
^"What you can expect to see as a £3 trillion asteroid passes Earth tonight". Retrieved 23 July 2015.
^"$5 Trillion Dollar Asteroid Makes Close Approach to Earth". Retrieved 23 July 2015.
^"How is it known that asteroid 2011 UW158 has so much platinum?". Retrieved 23 July 2015.
^(PDF). Archived from the original (PDF) on 19 August 2019. Retrieved 3 June 2017.
^"Ground-based radar observations of human space flight accessible targets". Retrieved 3 June 2017.
External linksedit
Asteroid Lightcurve Database (LCDB), query form (info 16 December 2017 at the Wayback Machine)
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
(436724) 2011 UW158 at NeoDyS-2, Near Earth Objects—Dynamic Site
Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters
January 01, 1970
436724, 2011, 436724, 2011, uw158, provisionally, known, 2011, uw158, stony, walnut, shaped, asteroid, fast, rotator, classified, near, earth, object, potentially, hazardous, asteroid, apollo, group, approximately, meters, diameter, discovered, october, 2011, . 436724 2011 UW158 provisionally known as 2011 UW158 is a stony walnut shaped asteroid and fast rotator classified as near Earth object and potentially hazardous asteroid of the Apollo group approximately 300 meters in diameter It was discovered on 25 October 2011 by Pan STARRS at Haleakala Observatory on the island of Maui Hawaii in the United States 2 436724 2011 UW158Animation of Arecibo radar images of 2011 UW158Discovery 1 Discovered byPan STARRS 1Discovery siteHaleakala Obs Discovery date25 October 2011DesignationsMPC designation 436724 2011 UW158Alternative designations2011 UW158Minor planet categoryApollo NEO PHA 1 2 Orbital characteristics 1 Epoch 4 September 2017 JD 2458000 5 Uncertainty parameter 0Observation arc5 48 yr 2 003 days Aphelion2 2301 AUPerihelion1 0109 AUSemi major axis1 6205 AUEccentricity0 3762Orbital period sidereal 2 06 yr 753 days Mean anomaly12 072 Mean motion0 28m 40 08s dayInclination4 5717 Longitude of ascending node286 00 Argument of perihelion8 7537 Earth MOID0 0020 AU 0 8 LDPhysical characteristicsDimensions0 22 0 04 km 3 0 3 0 6 km 4 0 311 km calculated 5 Synodic rotation period0 61069 0 00002 h 6 a 0 61070 0 00003 h 3 0 61073 h 5 0 610752 0 000001 h 7 Geometric albedo0 20 assumed 5 0 39 0 09 3 Spectral typeS 5 Absolute magnitude H 19 45 0 27 8 19 9 1 5 19 93 0 11 3 Contents 1 Orbital description 1 1 Close approach 2 Physical characteristics 2 1 Spectral type 2 2 Diameter and albedo 2 3 Fast rotator 2 4 Shape 3 Media attention 4 Notes 5 References 6 External linksOrbital description edit2011 UW158 orbits the Sun at a distance of 1 0 2 2 AU once every 2 years and 1 month 753 days Its orbit has an eccentricity of 0 38 and an inclination of 5 with respect to the ecliptic 1 Its observation arc begins with its official discovery observation by Pan STARRS as no precoveries were taken and no prior identifications were made 2 Close approach edit The asteroid has an Earth minimum orbit intersection distance of 0 0020 AU 300 000 km which corresponds to 0 8 lunar distances LD On 19 July 2015 it passed about 2 5 million kilometers from Earth 6 5 LD 1 attracting the interest of astronomers 1 The asteroid was listed as level 1 in the Torino Scale on 4 November 2011 9 days after its discovery but was removed two weeks later 9 10 nbsp nbsp Left Inner solar system orbits right Motion of 2011 UW158 across sky 6 hour motionPhysical characteristics editSpectral type edit 2011 UW158 is an assumed stony S type asteroid the most common type among the populations of near Earth and inner main belt asteroids 5 Diameter and albedo edit Bruce Gary at Hereford Arizona Observatory G95 estimated a mean diameter of 220 meters with a high albedo of 0 39 3 while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroid of 0 20 and calculates a mean diameter of 311 meters based on an absolute magnitude of 19 9 5 Fast rotator edit In July and August 2015 rotational lightcurves of this asteroid were obtained from photometric observations by Bruce Gary at Hereford Arizona Observatory and by Brian Warner at the CS3 Palmer Divide Station in California U82 Lightcurve analysis gave a rotation period of 0 6107 hours 36 6 minutes with a brightness variation between 0 52 and 2 05 magnitude U 3 3 3 3 6 a This makes 2011 UW158 one of the Top 200 fast rotator suggesting it is a large boulder rather than a rubble pile 6 11 Shape edit Radar observations by the Arecibo Observatory on 14 July 2015 revealed that the asteroid s shape looks like an unshelled walnut with a diameter of 300 by 600 metres The radiometric observations also agreed with the previously obtained photometric ones and gave a period of 37 minutes 4 11 Media attention editIt also attracted the media and even firms such as Planetary Resources 12 for its alleged content of platinum worth as high as 5 trillion U S dollars 13 14 15 Commenters at StackExchange have denied these estimations as being orders of magnitude too high 16 and radar observations have shown that the object contains no more metal than an average rocky asteroid 17 18 Notes edit a b Lightcurve plot of 2011 UW158 by Brian Warner at the CS3 Palmer Divide Station in July 2015 rotation period of 0 61069 0 00002 hours with an amplitude of 0 65 magnitudeReferences edit a b c d e f g JPL Small Body Database Browser 436724 2011 UW158 2017 04 19 last obs Jet Propulsion Laboratory Retrieved 2 June 2017 a b c 436724 2011 UW158 Minor Planet Center Retrieved 28 March 2017 a b c d e f Gary Bruce L January 2016 Unusual Properties for the NEA 436724 2011 UW158 The Minor Planet Bulletin 43 1 33 38 Bibcode 2016MPBu 43 33G ISSN 1052 8091 Retrieved 28 March 2017 a b Solar System Studies at Arecibo Observatory Arecibo Observatory Retrieved 23 July 2015 a b c d e f g LCDB Data for 436724 Asteroid Lightcurve Database LCDB Retrieved 28 March 2017 a b c Warner Brian D January 2016 Near Earth Asteroid Lightcurve Analysis at CS3 Palmer Divide Station 2015 June September The Minor Planet Bulletin 43 1 66 79 Bibcode 2016MPBu 43 66W ISSN 1052 8091 PMC 7244002 PMID 32455369 Retrieved 28 March 2017 Carbognani Albino Gary Bruce L Oey Julian Baj Giorgio Bacci Paolo January 2016 Pole and Shape for the NEA 436724 2011 UW158 The Minor Planet Bulletin 43 1 38 41 Bibcode 2016MPBu 43 38C ISSN 1052 8091 Retrieved 28 March 2017 Veres Peter Jedicke Robert Fitzsimmons Alan Denneau Larry Granvik Mikael Bolin Bryce et al November 2015 Absolute magnitudes and slope parameters for 250 000 asteroids observed by Pan STARRS PS1 Preliminary results Icarus 261 34 47 arXiv 1506 00762 Bibcode 2015Icar 261 34V doi 10 1016 j icarus 2015 08 007 S2CID 53493339 Retrieved 28 March 2017 2011 UW158 Impact Risk Near Earth Object Program NASA Archived from the original on 6 November 2011 NEOs Removed from Impact Risks Tables Near Earth Object Program NASA Archived from the original on 2 June 2002 Retrieved 28 March 2017 a b First detailed images of rare asteroid to pass close by Earth on 19 July Astronomy Now 19 July 2015 Retrieved 28 March 2017 Mining Firm Aiming For Platinum Loaded Asteroid Retrieved 23 July 2015 dead link UW 158 Watch live as asteroid worth 3 TRILLION passes close to Earth Retrieved 23 July 2015 What you can expect to see as a 3 trillion asteroid passes Earth tonight Retrieved 23 July 2015 5 Trillion Dollar Asteroid Makes Close Approach to Earth Retrieved 23 July 2015 How is it known that asteroid 2011 UW158 has so much platinum Retrieved 23 July 2015 5th IAA Planetary Defense Conference PDF Archived from the original PDF on 19 August 2019 Retrieved 3 June 2017 Ground based radar observations of human space flight accessible targets Retrieved 3 June 2017 External links editAsteroid Lightcurve Database LCDB query form info Archived 16 December 2017 at the Wayback Machine Dictionary of Minor Planet Names Google books Asteroids and comets rotation curves CdR Observatoire de Geneve Raoul Behrend 436724 2011 UW158 at NeoDyS 2 Near Earth Objects Dynamic Site Ephemerides Observation prediction Orbital info MOID Proper elements Observational info Close approaches Physical info Orbit animation 436724 2011 UW158 at ESA space situational awareness Ephemerides Observations Orbit Physical properties Summary 436724 2011 UW158 at the JPL Small Body DatabaseClose approach Discovery Ephemeris Orbit diagram Orbital elements Physical parameters Retrieved from https en wikipedia org w index php title 436724 2011 UW158 amp oldid 1218619211, wikipedia, wiki, book, books, library,
