(10302) 1989 ML

Near-Earth asteroid September 2020 yes (10302) 1989 ML 1989 ML CFHT 2015-12-13 crop.gif 1989ML photographed by the Canada–France–Hawaii Telescope in December 2015 #FFC2E0 E. F. Helin, J. Alu 29 June 1989 Palomar Observatory, United States 1992 WA Amor NEO 21 November 2025 (JD 2461000.5) 0 1.2728 AU Gm on 1.0985 AU Gm on 1.4470 AU Gm on on 0.1369 1.436 yr (524.518 d) 4.379° 104.272° 183.625° 121.513° 26.28 km/s 0.276 0.037 km 19.228 h d on X-type142E-type 19.45 (JPL) 0.37 0.15 0.686642 ms / day 12250 days (33.54 yr) 0.08233 AU (10302) 1989 ML is an unnamed near-Earth asteroid located in the inner Solar System. It is relatively small, estimated to be around 300 m ft in diameter. An Amor asteroid, it orbits between Earth and Mars. It is an X-type asteroid, so its precise surface composition is yet unknown, though telescopic observations indicate it may be relatively enriched in iron. It was discovered by Eleanor F. Helin and Jeff T. Alu at Palomar Observatory on 29 June 1989. 1989 ML was the former backup target for Japan's Hayabusa mission, but launch delays meant that the rendezvous had to be cancelled. Orbit thumb|left|A diagram of 1989 ML's orbit, with the orbits of the inner planets shown. 1989 ML is classified as a near-Earth object (NEO) and an Amor asteroid, meaning that its orbit never crosses the Earth's.489 It has a semi-major axis of 1.273 astronomical units (AU), completing an orbit around the Sun every 1.436 years (524.518 days). It has a moderately elliptical orbit with an orbital eccentricity of 0.137, with its distance from the Sun varying from 1.0985 AU to 1.273 AU. 1989 ML has a relatively low orbital inclination of 4.379° with respect to the ecliptic plane. Its proximity to Earth means that 1989 ML's orbit is strongly perturbed and chaotic; the Lyapunov time of its orbit is roughly 1,000 years. Physical characteristics In 2007, a team of astronomers led by Michael Mueller used observations from the Spitzer Space Telescope to estimate 1989 ML's physical properties. Adopting an absolute magnitude value of 19.5 0.3, Mueller et al. derived a diameter of 0.246 ± 0.037 km mi. Analysis of 1989 ML's lightcurve, or fluctuations in its observed brightness, indicate that it rotates once every 19.228 hours and has a tumbling rotation. The high amplitude of its lightcurve implies that it may be very elongated, with its longest axis being at least 2.2 times longer than its intermediate axis. Spectrum and surface Spectroscopic observations conducted by Palomar Observatory in 1999 revealed that 1989 ML has a relatively flat (or neutral) spectrum. As a result, a definitive interpretation of its surface composition could not be made, though its spectrum was noted to resemble dark, impact-shocked chondrites.144 Due to its neutral spectrum, 1989 ML was classified as an Xc-type asteroid under the Bus classification scheme, suggesting that it belongs to the E-type, M-type, or P-type classifications under the Tholen classification scheme.31 These asteroid types are spectrally degenerate, meaning that they can only be distinguished from each other by albedo. E-type asteroids have relatively high geometric albedos of 0.3–0.6; M-type asteroids have moderate albedos of 0.1–0.2; and P-type asteroids have dark albedos below 0.1, appearing to be rich in organic compounds. Mueller et al. estimated 1989 ML's geometric albedo to be 0.37 0.15, suggesting an E-type classification and ruling out a P-type classification. 1989 ML's optical and near-infrared colors were additionally compared to other asteroids, demonstrating that they differed from the color data of M-type and P-type asteroids. They also differed from the colors of the E-type asteroids 64 Angelina and 3103 Eger, but agreed with the color of 44 Nysa, another E-type asteroid. Nysa-type spectra are consistent with silicate mineralogy enriched in iron, whilst Angelina-type spectra are consistent with silicates containing sulfides, indicating that 1989 ML is relatively enriched in iron. Exploration 1989 ML is an attractive target for spacecraft exploration due to its relative accessibility from Earth. It was considered as a backup target of JAXA's sample-return mission Hayabusa (then MUSES-C), with the primary target being 4660 Nereus. However, both targets had to be given up due to launch delays.140, 143 Hayabusa would instead go on to rendezvous with 25143 Itokawa in 2005. 1989 ML was also considered by the European Space Agency as a candidate target for the Don Quijote mission concept to study the effects of impacting a spacecraft into an asteroid; however, they too changed to other targets. See also List of minor planets and comets visited by spacecraft References (10302) = 1989 ML = 1992 WA https://www.minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=10302 Minor Planet Center 2015-06-04 2 May 2025 https://web.archive.org/web/20250502175751/https://minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=10302 live https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=10302 10302 (1989 ML) JPL Small-Body Database NASA/Jet Propulsion Laboratory 31 March 2025 1 March 2023 https://archive.today/20230301082858/https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html%23/?sstr=2023A3&view=OPC#/?sstr=10302 live Sancho Study: Designing the Minimum Earth Escape Spacecraft http://www.esa.int/SPECIALS/NEO/SEMVXVB1S6F_0.html European Space Agency 23 May 2012 5 November 2009 17 October 2011 https://web.archive.org/web/20111017205713/http://www.esa.int/SPECIALS/NEO/SEMVXVB1S6F_0.html dead Mueller Michael Harris Alan W. Fitzsimmons Alan Size, albedo, and taxonomic type of potential spacecraft target Asteroid (10302) 1989 ML April 2007 Icarus 187 2 611–615 10.1016/j.icarus.2007.01.002 2007Icar..187..611M https://hal.archives-ouvertes.fr/hal-00499068/file/PEER_stage2_10.1016%252Fj.icarus.2007.01.002.pdf Binzel Richard P. Harris Alan W. Bus Schelte J. Burbine Thomas H. Spectral Properties of Near-Earth Objects: Palomar and IRTF Results for 48 Objects Including Spacecraft Targets (9969) Braille and (10302) 1989 ML June 2001 Icarus 151 2 139–149 10.1006/icar.2001.6613 2001Icar..151..139B Tholen, D.J. Barucci, M.A. 1989 Binzel, Richard P. Gehrels, Tom Matthews, Mildred Shapley Asteroid taxonomy Asteroids II University of Arizona Press 0-8165-1123-3 298–315 Patrick Michel Francesca E. DeMeo William F. Bottke Asteroids IV https://books.google.com/books?id=clnkCgAAQBAJ The Compositional Structure of the Asteroid Belt https://www.mit.edu/~fdemeo/publications/DeMeoetal2015_AIV.pdf F. E. DeMeo C. M. O'D. Alexander K. J. Walsh C. R. Chapman R. P. Binzel 2015 13–41 University of Arizona Press, Tucson 10.2458/azu_uapress_9780816532131-ch002 1506.04805 2015aste.book...13D 978-0-816-53213-1 Schubert Gerald Treatise on Geophysics 2nd 17 April 2015 Elsevier 978-0-444-53803-1 Asteroids and Comets Fernández Y. R. Li J. -Y. Howell E. S. Woodney L. M. 487–528 Yoshikawa M. Froeschlé Ch. Michel P. Orbital Evolution of Two Near-Earth Asteroids: Nereus and 1989 ML 2000 Advances in Space Research 25 2 273–276 10.1016/S0273-1177(99)00937-0 2000AdSpR..25..273Y Warner Brian D. Stephens Robert D. Near-Earth Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2022 March–June Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 49 4 274–279 2022MPBu...49..274W October 2022 Abe M. Sato I. Araki H. Lightcurve and Color of Near-Earth-Asteroid 1989ML 2000 Advances in Space Research 25 2 269–272 10.1016/S0273-1177(99)00938-2 2000AdSpR..25..269A Fujiwara A. et al. The Rubble-Pile Asteroid Itokawa as Observed by Hayabusa June 2006 Science 312 5778 1330–1334 10.1126/science.1125841 16741107 2006Sci...312.1330F External links Near-Earth asteroid Delta-v ranking, 1989 ML ranks fourth among the numbered asteroids 10302 10302 1989ML 10302 10301 Kataoka 10302 10303 Fréret 010302 Category:Discoveries by Eleanor F. Helin Category:Discoveries by Jeff T. Alu 010302 19890629 Category:E-type asteroids (Tholen)