(5645) 1990 SP

Eccentric and tumbling asteroid October 2019 yes (5645) 1990 SP #FFC2E0 20 September 1990 R. H. McNaught Siding Spring Obs. (5645) 1990 SP ApolloNEO 4 September 2017 (JD 2458000.5) 0 40.89 yr (14,935 days) 1.8798 AU 0.8302 AU 1.3550 AU 0.3873 1.58 yr (576 days) 339.42° 0.6249 ms / day 13.507° 45.762° 48.178° 0.0537 AU 1.648 km1.65 km (taken)1.668 0.018 km1.849 0.334 km2.20 0.74 km 30.39 0.04 h 0.06 0.080.062 0.0790.068 0.0320.08270.121 0.022 PCXTS 16.75 0.2 (R)16.817.117.20 0.317.24 0.206 (5645) 1990 SP is an eccentric and tumbling asteroid, classified as a near-Earth object of the Apollo group, approximately 1.7 kilometers in diameter. It was discovered on 20 September 1990, by Scottish–Australian astronomer Robert McNaught at the Siding Spring Observatory in Canberra, Australia. Scientists have said that it has a '1 in 364 billion chance' of colliding with the Earth. Orbit and classification The asteroid orbits the Sun at a distance of 0.8–1.9 AU once every 1 years and 7 months (576 days). Its orbit has an eccentricity of 0.39 and an inclination of 14° with respect to the ecliptic. Close approaches This near-Earth asteroid has an Earth minimum orbit intersection distance of 0.055 AU km on, only slightly above the threshold minimum distance of 19.5 lunar distances (0.05 AU) to make it a potentially hazardous object. It also makes close approaches to Mars. On 14 April 1969, it passed the Red Planet at only 0.013 AU km on 2. Precovery Published by the Digitized Sky Survey (DSS), a first precovery was taken at the discovering observatory in 1974, extending the asteroid's observation arc by 16 years prior to its discovery. Physical characteristics The stony S-type asteroid is also characterized as a P-type, based on post-cryogenic observations by the Spitzer Space Telescope, while observations at the NASA Infrared Telescope Facility using its SpeX instrument during a follow-up campaign of the Spitzer-observed objects between 2009 and 2012, gave it a C/X/T spectral type. Rotation In April 2002, Czech astronomer Petr Pravec obtained a rotational lightcurve from a photometric observations, which gave a relatively long period of 30.39 0.04 hours with a brightness variation of 0.7 in magnitude (U=2). The observations have also shown that the body is most likely in a tumbling motion. Diameter and albedo Estimates for the body's diameter range from 1.6 to 2.2 kilometers with an albedo for its surface between 0.06 and 0.12, according to observations made by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer and by the Spitzer Space Telescope. The Collaborative Asteroid Lightcurve Link takes the revised WISE data – an albedo of 0.0872 and a diameter of 1.65 kilometers – as the best of all available results. References 30em 2015-07-04 last obs. JPL Small-Body Database Browser: 5645 (1990 SP) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2005645 Jet Propulsion Laboratory 26 May 2017 5645 (1990 SP) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=5645 29 June 2016 5645 29 June 2016 6 Michael Mueller M. Delbo' J. L. Hora D. E. Trilling B. Bhattacharya W. F. Bottke S. Chesley J. P. Emery G. Fazio A. W. Harris A. Mainzer M. Mommert B. Penprase H. A. Smith T. B. Spahr J. A. Stansberry C. A. Thomas April 2011 ExploreNEOs. III. Physical Characterization of 65 Potential Spacecraft Target Asteroids The Astronomical Journal 141 4 9 2011AJ....141..109M 10.1088/0004-6256/141/4/109 https://authors.library.caltech.edu/23152/1/Mueller2011p13239Astron_J.pdf Petr Pravec Alan W. Harris Peter Kusnirák Adrián Galád Kamil Hornoch September 2012 Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations Icarus 221 1 365–387 2012Icar..221..365P 10.1016/j.icarus.2012.07.026 11104/0217021 free 6 A. Mainzer T. Grav J. Masiero J. Bauer R. M. Cutri R. S. McMillan C. R. Nugent D. Tholen R. Walker E. L. Wright November 2012 Physical Parameters of Asteroids Estimated from the WISE 3-Band Data and NEOWISE Post-Cryogenic Survey The Astrophysical Journal Letters 760 1 6 2012ApJ...760L..12M 10.1088/2041-8205/760/1/L12 1210.0502 41459166 6 A. Mainzer T. Grav J. Masiero E. Hand J. Bauer D. Tholen R. S. McMillan T. Spahr R. M. Cutri E. Wright J. Watkins W. Mo C. Maleszewski November 2011 NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results The Astrophysical Journal 741 2 25 2011ApJ...741...90M 10.1088/0004-637X/741/2/90 1109.6407 118700974 6 P. Pravec A. W. Harris P. Scheirich P. Kusnirák L. Sarounová C. W. Hergenrother S. Mottola M. D. Hicks G. Masi Yu. N. Krugly V. G. Shevchenko M. C. Nolan E. S. Howell M. Kaasalainen A. Galád P. Brown D. R. DeGraff J. V. Lambert W. R. Cooney S. Foglia January 2005 Tumbling asteroids Icarus 173 1 108–131 2005Icar..173..108P 10.1016/j.icarus.2004.07.021 6 C. A. Thomas D. E. Trilling J. P. Emery M. Mueller J. L. Hora L. A. M. Benner B. Bhattacharya W. F. Bottke S. Chesley M. Delbó G. Fazio A. W. Harris A. Mainzer M. Mommert A. Morbidelli B. Penprase H. A. Smith T. B. Spahr J. A. Stansberry September 2011 ExploreNEOs. V. Average Albedo by Taxonomic Complex in the Near-Earth Asteroid Population The Astronomical Journal 142 3 12 2011AJ....142...85T 10.1088/0004-6256/142/3/85 free Cristina A. Thomas Joshua P. Emery David E. Trilling Marco Delbó Joseph L. Hora Michael Mueller January 2014 Physical characterization of Warm Spitzer-observed near-Earth objects Icarus 228 217–246 2014Icar..228..217T 10.1016/j.icarus.2013.10.004 1310.2000 119278697 6 A. Mainzer T. Grav J. Bauer J. Masiero R. S. McMillan R. M. Cutri R. Walker E. Wright P. Eisenhardt D. J. Tholen T. Spahr R. Jedicke L. Denneau E. DeBaun D. Elsbury T. Gautier S. Gomillion E. Hand W. Mo J. Watkins A. Wilkins G. L. Bryngelson A. Del Pino Molina S. Desai M. Gómez Camus S. L. Hidalgo I. Konstantopoulos J. A. Larsen C. Maleszewski M. A. Malkan J.-C. Mauduit B. L. Mullan E. W. Olszewski J. Pforr A. Saro J. V. Scotti L. H. Wasserman December 2011 NEOWISE Observations of Near-Earth Objects: Preliminary Results The Astrophysical Journal 743 2 17 2011ApJ...743..156M 10.1088/0004-637X/743/2/156 1109.6400 239991 External links Asteroid Lightcurve Database (LCDB), query form (info https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html 16 December 2017 ) Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR https://web.archive.org/web/20160729213840/http://obswww.unige.ch/~behrend/page_cou.html 29 July 2016 – Observatoire de Genève, Raoul Behrend 5645 5645 1990SP 5644 Maureenbell 5645 (5646) 1990 TR 005645 Category:Discoveries by Robert H. McNaught 19900920