1981 Midas

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1981 Midas
Discovery [1]
Discovered by C. Kowal
Discovery site Palomar Obs.
Discovery date 6 March 1973
MPC designation 1981 Midas
Named after
Midas (mythology)[2]
1973 EA
Apollo · NEO · PHA[1]
Venus crosser
Mars crosser
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 41.97 yr (15,330 days)
Aphelion 2.9307 AU
Perihelion 0.6215 AU
1.7761 AU
Eccentricity 0.6501
2.37 yr (865 days)
0° 24m 59.04s / day
Inclination 39.833°
Earth MOID 0.0031 AU
Physical characteristics
Dimensions 1.95±0.07 km[3][4]
3.4 km (outdated)[1]
5.220 h[5]
5.22 h[6]
5.22 h[7]
0.2661 (derived)[4]
SMASS = V [1] · V[4]

1981 Midas, provisional designation 1973 EA, is a vestoid asteroid, classified as a near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter.[1] It was discovered on 6 March 1973, by American astronomer Charles Kowal at Palomar Observatory in San Diego County, California.[10] In 1987 it was also detected by radar from Goldstone Deep Space Communications Complex at a distance of 0.08 AU with a measured maximal radar cross-section of 0.1 km2.[11]

The moderately bright V-type asteroid is also an Apollo asteroid, as well as a Venus and Mars-crosser. The asteroid orbits the Sun at a distance of 0.6–2.9 AU every 2 years and 4 months (865 days). It has a low minimum orbit intersection distance with Earth of 0.0039 AU (580,000 km; 360,000 mi), which corresponds to 1.55 lunar distance (Earth–Moon distance). However, it does not pose an impact risk for the foreseable future. Its last notable close approach to Earth was on 11 March 1992 passing 0.13332 AU (19,944,000 km; 12,393,000 mi) from Earth.[12] The next notable close approach will be on 21 March 2018 passing 0.08957 AU (13,399,000 km; 8,326,000 mi) from Earth[12] and shining at an apparent magnitude of +12.4.[13] As no precoveries were taken, the asteroid's observation arc begins with its discovery observation at Palomar in 1973.[10]

Three rotational light-curves obtained from photometric observations gave a concurring rotation period of 5.24 hours with a relatively high brightness variation of 0.65, 0.8 and 0.87 in magnitude, respectively (U=3/2/3).[5][6][7] According to the survey carried out by the Japanese Akari satellite, the asteroid measures 1.95 kilometers in diameter and its surface has an albedo of 0.293,[3] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.266 and calculates an identical diameter of 1.95 kilometers, based on an absolute magnitude of 15.6.[4]

The asteroid is named after the figure from Greek mythology, Midas, the King of Phrygia, who turned whatever he touched to gold. He received this ability as an award, but soon realized that this gift was a curse when his daughter turned into a statue after he had touched her. Relieved of his power by bathing in the river Pactolus, other accounts also tell his death caused by starvation.[2] Naming citation was published before November 1977 (M.P.C. 4237).[14]


  1. ^ a b c d e f g "JPL Small-Body Database Browser: 1981 Midas (1973 EA)" (2015-02-24 last obs.). Jet Propulsion Laboratory. Retrieved 18 September 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1981) Midas. Springer Berlin Heidelberg. p. 160. ISBN 978-3-540-00238-3. Retrieved 18 September 2016. 
  3. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; Ishihara, Daisuke; Kataza, Hirokazu; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 26 December 2015. 
  4. ^ a b c d e "LCDB Data for (1981) Midas". Asteroid Lightcurve Database (LCDB). Retrieved 18 September 2016. 
  5. ^ a b c Mottola, S.; de Angelis, G.; di Martino, M.; Erikson, A.; Harris, A. W.; Hahn, G.; Neukum, G.; Pravec, P.; Wolf, M. (March 1995). "The EUNEASO Photometric Follow-up Program". Abstracts of the Lunar and Planetary Science Conference. Bibcode:1995LPI....26.1003M. Retrieved 26 December 2015. 
  6. ^ a b c Wisniewski, W. Z.; Michalowski, T. M.; Harris, A. W.; McMillan, R. S. (March 1995). "Photoelectric Observations of 125 Asteroids". Abstracts of the Lunar and Planetary Science Conference. Bibcode:1995LPI....26.1511W. Retrieved 26 December 2015. 
  7. ^ a b Torppa, J.; Aksnes, K.; Dai, Z.; Grav, T.; Hahn, G.; Laakso, T.; Lagerkvist, C.-I.; Muinonen, K.; et al. (August 2005). "Spins and Shapes of Potentially Hazardous Asteroids". American Astronomical Society. 37: 643. Bibcode:2005DPS....37.1526T. Retrieved 26 December 2015. 
  8. ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 17 December 2015. 
  9. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762free to read. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 18 September 2016. 
  10. ^ a b "1981 Midas (1973 EA)". Minor Planet Center. Retrieved 18 September 2016. 
  11. ^ Ostro, S. J.; et al. (October 1991), "Asteroid radar astrometry", Astronomical Journal, 102, pp. 1490–1502, Bibcode:1991AJ....102.1490O, doi:10.1086/115975. 
  12. ^ a b "JPL Close-Approach Data: 1981 Midas (1973 EA)" (2013-12-30 last obs). Retrieved 2014-01-31. 
  13. ^ "(1981) Midas Ephemerides for 15 Feb 2018 through 15 Apr 2018". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 2014-01-31. 
  14. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 18 September 2016. 

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