(121514) 1999 UJ7 is a small asteroid orbiting near the L4 point of Mars (60 degrees ahead Mars on its orbit).[2] As of April 2024, it is one of only two known asteroids to orbit the leading L4 point of Mars — the other being 2023 FW14[4] — although at least 15 other asteroids orbit Mars's trailing L5 point: The largest being 5261 Eureka, (101429) 1998 VF31, and 2007 NS2.[2] Not only does (121514) 1999 UJ7 orbit on the other side of Mars from other similar asteroids, its spectrum is different as well, which is puzzling because all of the Martiantrojans seem to be in very stable orbits.[3]
Animation of 1999 UJ7 relative to Sun and Mars 1600-2500 Sun· 1999 UJ7· Mars
(121514) 1999 UJ7 orbits around the L4 point of Mars in a very stable orbit and is large enough that the Yarkovsky effect will not affect its orbit.[2]
Physical characteristicsedit
Due to similarity in the measured brightness of (121514) 1999 UJ7 with other Martian trojans, it is thought to be a small asteroid with an effective diameter on the order of 1 kilometer (0.62 mi).[2] Its spectrum suggests that it is an X-type asteroid, which is different from 5261 Eureka and 1998 VF31,[3] and is somewhat puzzling since different mineral compositions suggest different origins for the two groups of asteroids. The long lifetime of the orbits for these asteroids makes the possibility of one or more of them being interlopers unlikely, however. This suggests that either one or more of the Martian trojans was captured in such a way as to give it a long-term stable orbit (and it is therefore not a primordial Martian asteroid), or that some fusion or combination of previous asteroids resulted in the presently observed ones.[3] The Yarkovsky effect may provide a potential capture mechanism but not enough is known about the shapes of these objects to provide a useful Yarkovsky model.[3]
^ abcdeScholl, H.; Marzari, F.; Tricarico, P. (June 2005). (PDF). Icarus. 175 (2): 397–408. Bibcode:2005Icar..175..397S. doi:10.1016/j.icarus.2005.01.018. Archived from the original (PDF) on 16 February 2012. Retrieved 22 April 2009.
^ abcdeRivkin, A. S.; Binzel, R. P.; Howell, E. S.; Bus, S. J.; Grier, J. A. (October 2003). "Spectroscopy and photometry of Mars Trojans". Icarus. 165 (2): 349–354. Bibcode:2003Icar..165..349R. doi:10.1016/S0019-1035(03)00211-2.
^de la Fuente Marcos, Raúl; de León, Julia; de la Fuente Marcos, Carlos; Alarcon, Miguel R.; Licandro, Javier; Serra-Ricart, Miquel; Geier, Stefan; Cabrera-Lavers, Antonio (21 March 2024). "Dynamics of 2023 FW14, the second L4 Mars trojan, and a physical characterization using the 10.4 m Gran Telescopio Canarias". Astronomy & Astrophysics, Letters to the Editor. 683 (1): L14 (6 pages). arXiv:2403.04061. Bibcode:2024A&A...683L..14D. doi:10.1051/0004-6361/202449688.{{cite journal}}: CS1 maint: date and year (link)
External linksedit
(121514) 1999 UJ7 at AstDyS-2, Asteroids—Dynamic Site
Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
121514, 1999, 121514, 1999, small, asteroid, orbiting, near, point, mars, degrees, ahead, mars, orbit, april, 2024, only, known, asteroids, orbit, leading, point, mars, other, being, 2023, fw14, although, least, other, asteroids, orbit, mars, trailing, point, . 121514 1999 UJ7 is a small asteroid orbiting near the L4 point of Mars 60 degrees ahead Mars on its orbit 2 As of April 2024 it is one of only two known asteroids to orbit the leading L4 point of Mars the other being 2023 FW14 4 although at least 15 other asteroids orbit Mars s trailing L5 point The largest being 5261 Eureka 101429 1998 VF31 and 2007 NS2 2 Not only does 121514 1999 UJ7 orbit on the other side of Mars from other similar asteroids its spectrum is different as well which is puzzling because all of the Martian trojans seem to be in very stable orbits 3 121514 1999 UJ7Discovery 1 Discovered by30 October 1999 by LINEARDiscovery siteSocorroDiscovery date30 October 1999DesignationsAlternative designations2002 AC180 1 Minor planet categoryMartian L4Orbital characteristics 1 Epoch 13 January 2016 JD 2457400 5 Uncertainty parameter 0Observation arc21861 days 59 85 yr Aphelion1 5843517 AU 237 01564 Gm Perihelion1 4644704 AU 219 08165 Gm Semi major axis1 5244110 AU 228 04864 Gm Eccentricity0 0393206Orbital period sidereal 1 88 yr 687 47 d Mean anomaly229 9277 Mean motion0 31m 25 183s dayInclination16 75044 Longitude of ascending node347 37714 Argument of perihelion48 35771 Earth MOID0 47372 AU 70 868 Gm Jupiter MOID3 49473 AU 522 804 Gm Physical characteristicsDimensions 1 km 2 Spectral typeX 3 Absolute magnitude H 16 9 1 Contents 1 Orbit 2 Physical characteristics 3 See also 4 References 5 External linksOrbit edit nbsp Animation of 1999 UJ7 relative to Sun and Mars 1600 2500 Sun 1999 UJ7 Mars 121514 1999 UJ7 orbits around the L4 point of Mars in a very stable orbit and is large enough that the Yarkovsky effect will not affect its orbit 2 Physical characteristics editDue to similarity in the measured brightness of 121514 1999 UJ7 with other Martian trojans it is thought to be a small asteroid with an effective diameter on the order of 1 kilometer 0 62 mi 2 Its spectrum suggests that it is an X type asteroid which is different from 5261 Eureka and 1998 VF31 3 and is somewhat puzzling since different mineral compositions suggest different origins for the two groups of asteroids The long lifetime of the orbits for these asteroids makes the possibility of one or more of them being interlopers unlikely however This suggests that either one or more of the Martian trojans was captured in such a way as to give it a long term stable orbit and it is therefore not a primordial Martian asteroid or that some fusion or combination of previous asteroids resulted in the presently observed ones 3 The Yarkovsky effect may provide a potential capture mechanism but not enough is known about the shapes of these objects to provide a useful Yarkovsky model 3 See also edit5261 Eureka 1990 MB 101429 1998 VF31 311999 2007 NS2 385250 2001 DH47 2009 SE 2011 SC191 2011 SL25 2011 SP189 2011 UB256 2011 UN63 2016 CP31 2018 EC4 2018 FC4 2020 VT1References edit a b c d JPL Small Body Database Browser 121514 1999 UJ7 NASA Jet Propulsion Laboratory Retrieved 7 April 2016 a b c d e Scholl H Marzari F Tricarico P June 2005 Dynamics of Mars Trojans PDF Icarus 175 2 397 408 Bibcode 2005Icar 175 397S doi 10 1016 j icarus 2005 01 018 Archived from the original PDF on 16 February 2012 Retrieved 22 April 2009 a b c d e Rivkin A S Binzel R P Howell E S Bus S J Grier J A October 2003 Spectroscopy and photometry of Mars Trojans Icarus 165 2 349 354 Bibcode 2003Icar 165 349R doi 10 1016 S0019 1035 03 00211 2 de la Fuente Marcos Raul de Leon Julia de la Fuente Marcos Carlos Alarcon Miguel R Licandro Javier Serra Ricart Miquel Geier Stefan Cabrera Lavers Antonio 21 March 2024 Dynamics of 2023 FW14 the second L4 Mars trojan and a physical characterization using the 10 4 m Gran Telescopio Canarias Astronomy amp Astrophysics Letters to the Editor 683 1 L14 6 pages arXiv 2403 04061 Bibcode 2024A amp A 683L 14D doi 10 1051 0004 6361 202449688 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint date and year link External links edit 121514 1999 UJ7 at AstDyS 2 Asteroids Dynamic Site Ephemeris Observation prediction Orbital info Proper elements Observational info 121514 1999 UJ7 at the JPL Small Body DatabaseClose approach Discovery Ephemeris Orbit diagram Orbital elements Physical parameters Portal nbsp Solar System Retrieved from https en wikipedia org w index php title 121514 1999 UJ7 amp oldid 1217096356, wikipedia, wiki, book, books, library,
