Naiad/ˈneɪəd/, (also known as Neptune III and previously designated as S/1989 N 6) named after the naiads of Greek legend,[11] is the innermost satellite of Neptune and the nearest to the center of any gas giant with moons with a distance of 48,224 km from the planet's center. Its orbital period is less than a Neptunian day, resulting in tidal dissipation that will cause its orbit to decay. Eventually it will either crash into Neptune's atmosphere or break up to become a new ring. [12]
Naiad
Naiad as seen by Voyager 2 (elongation is due to smearing)
Naiad was discovered sometime before mid-September 1989 from the images taken by the Voyager 2probe. The last moon to be discovered during the flyby, it was designated S/1989 N 6.[13] The discovery was announced on 29 September 1989, in the IAU Circular No. 4867, and mentions "25 frames taken over 11 days", implying a discovery date of sometime before 18 September. The name was given on 16 September 1991.[14]
Physical characteristics
Naiad is irregularly shaped. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit.[15]
Orbit
Depiction of Naiad's orbital motion (red) in a view that co-rotates with Thalassa (central yellow dot)
Naiad is in a 73:69 orbital resonance with the next outward moon, Thalassa, in a "dance of avoidance". As it orbits Neptune, the more inclined Naiad successively passes Thalassa twice from above and then twice from below, in a cycle that repeats every ~21.5 Earth days. The two moons are about 3540 km apart when they pass each other. Although their orbital radii differ by only 1850 km, Naiad swings ~2800 km above or below Thalassa's orbital plane at closest approach. Thus this resonance, like many such orbital correlations, serves to stabilize the orbits by maximizing separation at conjunction. However, the role of orbital inclination in maintaining this avoidance in a case where eccentricities are minimal is unusual.[16][9]
Exploration
Since the Voyager 2 flyby, the Neptune system has been extensively studied from ground-based observatories and the Hubble Space Telescope as well. In 2002–03 the Keck telescope observed the system using adaptive optics and detected easily the largest four inner satellites. Thalassa was found with some image processing, but Naiad was not located.[17] Hubble has the ability to detect all the known satellites and possible new satellites even dimmer than those found by Voyager 2. On 8 October 2013 the SETI Institute announced that Naiad had been located in archived Hubble imagery from 2004.[18] The suspicion that the loss of positioning was due to considerable errors in Naiad's ephemeris[19] proved correct as Naiad was ultimately located 80 degrees from its expected position.
References
^Noah Webster (1884) A Practical Dictionary of the English Language
^ Jacobson, R. A.; Owen, W. M., Jr. (2004). "The orbits of the inner Neptunian satellites from Voyager, Earthbased, and Hubble Space Telescope observations". Astronomical Journal. 128 (3): 1412–1417. Bibcode:2004AJ....128.1412J. doi:10.1086/423037.
^ abShowalter, M. R.; de Pater, I.; Lissauer, J. J.; French, R. S. (2019). "The seventh inner moon of Neptune" (PDF). Nature. 566 (7744): 350–353. Bibcode:2019Natur.566..350S. doi:10.1038/s41586-019-0909-9. PMC6424524. PMID 30787452.
^ ab Karkoschka, E. (2003). "Sizes, shapes, and albedos of the inner satellites of Neptune". Icarus. 162 (2): 400–407. Bibcode:2003Icar..162..400K. doi:10.1016/S0019-1035(03)00002-2.
^ Williams, D. R. (2008-01-22). "Neptunian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 2008-12-13.
^ ab Brozović, M.; Showalter, M. R.; Jacobson, R. A.; French, R. S.; Lissauer, J. J.; de Pater, I. (October 31, 2019). "Orbits and resonances of the regular moons of Neptune". Icarus. 338 (2): 113462. arXiv:1910.13612. Bibcode:2020Icar..33813462B. doi:10.1016/j.icarus.2019.113462. S2CID 204960799.
^ ab "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 2008-10-24. Retrieved November 15, 2019.
^ "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Retrieved 2006-08-05.
^"Naiad". NASA Science Solar System Exploration. NASA.
^ Green, D. W. E. (September 29, 1989). "Neptune". IAU Circular. 4867. Retrieved 2011-10-26.
^ Marsden, B. G. (September 16, 1991). "Satellites of Saturn and Neptune". IAU Circular. 5347. Retrieved 2011-10-26.
^ Banfield, D.; Murray, N. (October 1992). "A dynamical history of the inner Neptunian satellites". Icarus. 99 (2): 390–401. Bibcode:1992Icar...99..390B. doi:10.1016/0019-1035(92)90155-Z.
^ "NASA Finds Neptune Moons Locked in 'Dance of Avoidance'". Jet Propulsion Laboratory. November 14, 2019. Retrieved November 15, 2019.
^ Marchis, F.; Urata, R.; de Pater, I.; Gibbard, S.; Hammel, H. B.; Berthier, J. (May 2004). "Neptunian Satellites observed with Keck AO system". American Astronomical Society, DDA meeting #35, #07.08; Bulletin of the American Astronomical Society. Vol. 36. p. 860. Bibcode:2004DDA....35.0708M.
^"Lost Neptune Moon Re-Discovered". Retrieved 9 October 2013.
^ Showalter, M. R.; Lissauer, J. J.; de Pater, I. (August 2005). "The Rings of Neptune and Uranus in the Hubble Space Telescope". American Astronomical Society, DPS meeting #37, #66.09; Bulletin of the American Astronomical Society. Vol. 37. p. 772. Bibcode:2005DPS....37.6609S.
External links
Wikimedia Commons has media related to Naiad (moon).
Neptune Moon Dance (animation) on YouTube from NASA Jet Propulsion Laboratory
January 06, 2023
naiad, moon, naiad, also, known, neptune, previously, designated, 1989, named, after, naiads, greek, legend, innermost, satellite, neptune, nearest, center, giant, with, moons, with, distance, from, planet, center, orbital, period, less, than, neptunian, resul. Naiad ˈ n eɪ e d also known as Neptune III and previously designated as S 1989 N 6 named after the naiads of Greek legend 11 is the innermost satellite of Neptune and the nearest to the center of any gas giant with moons with a distance of 48 224 km from the planet s center Its orbital period is less than a Neptunian day resulting in tidal dissipation that will cause its orbit to decay Eventually it will either crash into Neptune s atmosphere or break up to become a new ring 12 NaiadNaiad as seen by Voyager 2 elongation is due to smearing DiscoveryDiscovered byVoyager Imaging TeamDiscovery dateSeptember 1989DesignationsDesignationNeptune IIIPronunciation ˈ n eɪ e d or ˈ n aɪ ae d 1 2 ˈ n eɪ e d or ˈ n aɪ e d 3 Named afterpl Naiades NaiadesAdjectivesNaiadian ˈ ae d i e n 4 Orbital characteristics 5 6 Epoch 18 August 1989Semi major axis48 224 41 kmEccentricity0 0047 0 0018Orbital period sidereal 0 2943958 0 0000002 dInclination4 75 0 03 to Neptune equator 4 75 to local Laplace plane Satellite ofNeptunePhysical characteristicsDimensions96 60 52 km 7 8 Mean radius30 2 3 2 km 6 Mean density0 8 0 48 g cm3 9 Synodic rotation periodsynchronousAxial tiltzeroAlbedo0 072 7 10 Temperature 51 K mean estimate Apparent magnitude23 91 10 Contents 1 History 2 Physical characteristics 3 Orbit 4 Exploration 5 References 6 External linksHistory Edit Simulated view of Naiad Naiad was discovered sometime before mid September 1989 from the images taken by the Voyager 2 probe The last moon to be discovered during the flyby it was designated S 1989 N 6 13 The discovery was announced on 29 September 1989 in the IAU Circular No 4867 and mentions 25 frames taken over 11 days implying a discovery date of sometime before 18 September The name was given on 16 September 1991 14 Physical characteristics EditNaiad is irregularly shaped It is likely that it is a rubble pile re accreted from fragments of Neptune s original satellites which were smashed up by perturbations from Triton soon after that moon s capture into a very eccentric initial orbit 15 Orbit Edit Depiction of Naiad s orbital motion red in a view that co rotates with Thalassa central yellow dot Naiad is in a 73 69 orbital resonance with the next outward moon Thalassa in a dance of avoidance As it orbits Neptune the more inclined Naiad successively passes Thalassa twice from above and then twice from below in a cycle that repeats every 21 5 Earth days The two moons are about 3540 km apart when they pass each other Although their orbital radii differ by only 1850 km Naiad swings 2800 km above or below Thalassa s orbital plane at closest approach Thus this resonance like many such orbital correlations serves to stabilize the orbits by maximizing separation at conjunction However the role of orbital inclination in maintaining this avoidance in a case where eccentricities are minimal is unusual 16 9 Exploration EditSince the Voyager 2 flyby the Neptune system has been extensively studied from ground based observatories and the Hubble Space Telescope as well In 2002 03 the Keck telescope observed the system using adaptive optics and detected easily the largest four inner satellites Thalassa was found with some image processing but Naiad was not located 17 Hubble has the ability to detect all the known satellites and possible new satellites even dimmer than those found by Voyager 2 On 8 October 2013 the SETI Institute announced that Naiad had been located in archived Hubble imagery from 2004 18 The suspicion that the loss of positioning was due to considerable errors in Naiad s ephemeris 19 proved correct as Naiad was ultimately located 80 degrees from its expected position References Edit Noah Webster 1884 A Practical Dictionary of the English Language naiad Oxford English Dictionary Online ed Oxford University Press Subscription or participating institution membership required naiad Merriam Webster Dictionary Morris 1904 British violin makers Jacobson R A Owen W M Jr 2004 The orbits of the inner Neptunian satellites from Voyager Earthbased and Hubble Space Telescope observations Astronomical Journal 128 3 1412 1417 Bibcode 2004AJ 128 1412J doi 10 1086 423037 a b Showalter M R de Pater I Lissauer J J French R S 2019 The seventh inner moon of Neptune PDF Nature 566 7744 350 353 Bibcode 2019Natur 566 350S doi 10 1038 s41586 019 0909 9 PMC 6424524 PMID 30787452 a b Karkoschka E 2003 Sizes shapes and albedos of the inner satellites of Neptune Icarus 162 2 400 407 Bibcode 2003Icar 162 400K doi 10 1016 S0019 1035 03 00002 2 Williams D R 2008 01 22 Neptunian Satellite Fact Sheet NASA National Space Science Data Center Retrieved 2008 12 13 a b Brozovic M Showalter M R Jacobson R A French R S Lissauer J J de Pater I October 31 2019 Orbits and resonances of the regular moons of Neptune Icarus 338 2 113462 arXiv 1910 13612 Bibcode 2020Icar 33813462B doi 10 1016 j icarus 2019 113462 S2CID 204960799 a b Planetary Satellite Physical Parameters JPL Solar System Dynamics 2008 10 24 Retrieved November 15 2019 Planet and Satellite Names and Discoverers Gazetteer of Planetary Nomenclature USGS Astrogeology July 21 2006 Retrieved 2006 08 05 Naiad NASA Science Solar System Exploration NASA Green D W E September 29 1989 Neptune IAU Circular 4867 Retrieved 2011 10 26 Marsden B G September 16 1991 Satellites of Saturn and Neptune IAU Circular 5347 Retrieved 2011 10 26 Banfield D Murray N October 1992 A dynamical history of the inner Neptunian satellites Icarus 99 2 390 401 Bibcode 1992Icar 99 390B doi 10 1016 0019 1035 92 90155 Z NASA Finds Neptune Moons Locked in Dance of Avoidance Jet Propulsion Laboratory November 14 2019 Retrieved November 15 2019 Marchis F Urata R de Pater I Gibbard S Hammel H B Berthier J May 2004 Neptunian Satellites observed with Keck AO system American Astronomical Society DDA meeting 35 07 08 Bulletin of the American Astronomical Society Vol 36 p 860 Bibcode 2004DDA 35 0708M Lost Neptune Moon Re Discovered Retrieved 9 October 2013 Showalter M R Lissauer J J de Pater I August 2005 The Rings of Neptune and Uranus in the Hubble Space Telescope American Astronomical Society DPS meeting 37 66 09 Bulletin of the American Astronomical Society Vol 37 p 772 Bibcode 2005DPS 37 6609S External links Edit Wikimedia Commons has media related to Naiad moon Naiad Profile by NASA s Solar System Exploration Neptune s Known Satellites by Scott S Sheppard Archival Hubble Images Reveal Neptune s Lost Inner Moon SETI October 8 2013 Neptune Moon Dance animation on YouTube from NASA Jet Propulsion Laboratory Retrieved from https en wikipedia org w index php title Naiad moon amp oldid 1126027931, wikipedia, wiki, book, books, library,
