(162058) 1997 AE12

Asteroid March 2020 yes (162058) 1997 AE 12 #FFC2E0 1997 AE 12 imaged on 16 August 2003 10 January 1997 Spacewatch Kitt Peak National Obs. (162058) 1997 AE 12 NEO Amor 4 September 2017 (JD 2458000.5) 0 22.50 yr (8,218 days) 3.6785 AU 1.0554 AU 2.3670 AU 0.5541 3.64 yr (1,330 days) 296.49° 0.2707 ms / day 4.8519° 304.82° 60.820° 0.0881 AU (34.3 LD) 0.782 km (calculated) 0.847 0.013 km 1880 595 hlcdb-Pravec-2003 0.186 0.020 0.20 (assumed) S QJuly 2017 17.8 17.9 (162058) 1997 AE 12 is a stony, sub-kilometer asteroid and likely the slowest rotator known to exist. It is classified as a near-Earth object of the Amor group and measures approximately 800 meters in diameter. The asteroid was discovered on 10 January 1997 by the Spacewatch survey at Kitt Peak National Observatory near Tucson, Arizona. Orbit and classification 1997 AE 12 is an Amor asteroid, a group of near-Earth object that approach the orbit of Earth from beyond, but do not cross it. It orbits the Sun at a distance of 1.1–3.7 AU once every 3 years and 8 months (1,330 days). Its orbit has an eccentricity of 0.55 and an inclination of 5° with respect to the ecliptic. Published by the Digitized Sky Survey, a first precovery was taken at the Australian Siding Spring Observatory in July 1992, extending the body's observation arc by more than 4 years prior to its official discovery observation at Kitt Peak. Close approaches 1997 AE 12 occasionally makes close approaches to Earth and Mars. It has an Earth minimum orbital intersection distance of 0.0881 AU km on 3, which is about 34.3 lunar distances. Its closest recorded approach to Earth took place on 30 August 2003, when the asteroid came within 0.1238 AU km on 3 from Earth. It will come closer still on 8 October 2145, when it will be within 0.1042 AU km on from Earth. The asteroid will make its closest approach to Mars on 29 December 2054 when it will come within 0.0376 AU km on 3 from the planet. Physical properties Spectral type 1997 AE 12 is a rare Q-type asteroid with a very dark surface, reflecting only about 7% of the light it receives.July 2017 It has also been described a common stony S-type asteroid. Rotation The most unusual feature of 1997 AE 12, however, is its exceptionally slow rotation period of 1880 595 hours, or approximately 11 weeks (U=2).lcdb-Pravec-2003 It holds the record for being the slowest-rotating asteroid discovered so far. Its precise period with a smaller error margin still needs to be determined. The lightcurve also showed a high brightness variation of at least 0.6 magnitude, which is indicative for a non-spherical shape.lcdb-Pravec-2003 The asteroid may also be in a tumbling motion, but observations are not sufficient to determine any non-principal axis rotation. Like other slowly-rotating asteroids such as 912 Maritima, it is possible that the extremely long period of this asteroid is caused by YORP radiation pressure slowing down the asteroid's rotation. This is especially likely considering that 1997 AE 12 has a very low albedo, which would allow it to absorb more radiant energy from the Sun. Furthermore, the YORP effect has also been observed on other Q-type asteroids such as 1862 Apollo. Diameter and albedo According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 1997 AE 12 measures 0.847 kilometers in diameter and its surface has an albedo of 0.186. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 0.782 kilometers based on an absolute magnitude of 17.9. Naming As of 2017, this asteroid remains unnamed. Notes lcdb-Pravec-2003 Pravec (2003) web: rotation period 1880 595 hours with a brightness amplitude of 0.6 mag. Quality code of 2. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (162058) and Pravec's unpublished data comment:"P=1880 h derived assuming a symmetric curve, error perhaps a couple hundred hours. PAR=0. Ampl >0.6 mag" References 30em 2015-01-27 last obs. JPL Small-Body Database Browser: 162058 (1997 AE12) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2162058 Jet Propulsion Laboratory 25 July 2017 (162058) 1997AE12 University of Pisa NEODyS https://newton.spacedys.com/neodys/index.php?pc=1.1.0&n=162058 25 November 2015 162058 (1997 AE12) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=162058 22 August 2016 Higgins David Martinez, Luis Period Determination of Asteroid 912 Maritima The Minor Planet Bulletin 1052-8091 38 2 78–79 2011 2011MPBu...38...78H Kaasalainen, Mikko Ďurech, Josef Warner, Brian D. Krugly, Yurij N. Gaftonyuk, Ninel M. 2007 Acceleration of the rotation of asteroid 1862 Apollo by radiation torques Nature 446 7134 420–422 10.1038/nature05614 2007Natur.446..420K 17344861 4420270 162058 25 July 2017 6 P. Pravec P. Scheirich J. Durech J. Pollock P. Kusnirák K. Hornoch A. Galád D. Vokrouhlický A. W. Harris E. Jehin J. Manfroid C. Opitom M. Gillon F. Colas J. Oey J. Vrastil D. Reichart K. Ivarsen J. Haislip A. LaCluyze May 2014 The tumbling spin state of (99942) Apophis http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014Icar..233...48P Icarus 233 48–60 2014Icar..233...48P 10.1016/j.icarus.2014.01.026 25 July 2017 6 C. R. Nugent A. Mainzer J. Masiero J. Bauer R. M. Cutri T. Grav E. Kramer S. Sonnett R. Stevenson E. L. Wright December 2015 NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015ApJ...814..117N The Astrophysical Journal 814 2 13 2015ApJ...814..117N 10.1088/0004-637X/814/2/117 1509.02522 9341381 25 July 2017 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 162058 162058 1997AE12 162058 162058 162058 162058 162058 19970110