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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]

1981 Midas
Discovery [1]
Discovered byC. Kowal
Discovery sitePalomar Obs.
Discovery date6 March 1973
MPC designation(1981) Midas
Named after
Midas (Greek mythology)[2]
1973 EA
Apollo · NEO · PHA[1][3]
Venus- and Mars-crosser
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc41.97 yr (15,330 days)
Aphelion2.9307 AU
Perihelion0.6212 AU
1.7759 AU
2.37 yr (864 days)
0° 24m 59.4s / day
Earth MOID0.0045 AU · 1.8 LD
Physical characteristics
Dimensions1.95±0.07 km[4][5]
3.4 km (outdated)[1]
5.220 h[6]
5.22 h[7]
0.2661 (derived)[5]
SMASS = V [1] · V[5]
15.18[6] · 15.2[1] · 15.50[4] · 15.6±0.2[5][8][9] · 15.96±0.23[10]

It was discovered on 6 March 1973, by American astronomer Charles Kowal at Palomar Observatory in San Diego County, California.[3] It was named after King Midas from Greek mythology.[2]


Classification and orbitEdit

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 once every 2 years and 4 months (864 days). Its orbit has an eccentricity of 0.65 and an inclination of 40° with respect to the ecliptic.[1]

Midas has a low minimum orbit intersection distance with Earth of 0.0036 AU (540,000 km; 330,000 mi), which corresponds to 1.5 lunar distance (Earth–Moon distance). However, it does not pose an impact risk for the foreseeable 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.[11] The last notable close approach was on 21 March 2018 passing 0.08957 AU (13,399,000 km; 8,326,000 mi) from Earth[11] and shining at an apparent magnitude of +12.4.[12] The next notable close approach will be on 14 September 2032 passing slightly closer at 0.08635 AU (12,918,000 km; 8,027,000 mi) from Earth.[11] As no precoveries were taken, the asteroid's observation arc begins with its discovery observation at Palomar in 1973.[3]

Physical characteristicsEdit

Three rotational lightcurves 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).[7][6][8]

According to the survey carried out by the Japanese Akari satellite, Midas measures 1.95 kilometers in diameter and its surface has an albedo of 0.293,[4] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.266 and calculates an identical diameter of 1.95 kilometers with an absolute magnitude of 15.6.[5]

In 1987, Midas 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.[13]


This minor planet was 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] The approved naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 4237).[14]


  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 1981 Midas (1973 EA)" (2015-02-24 last obs.). Jet Propulsion Laboratory. Retrieved 1 July 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1981) Midas". Dictionary of Minor Planet Names – (1981) Midas. Springer Berlin Heidelberg. p. 160. doi:10.1007/978-3-540-29925-7_1982. ISBN 978-3-540-00238-3.
  3. ^ a b c "1981 Midas (1973 EA)". Minor Planet Center. Retrieved 18 September 2016.
  4. ^ 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.
  5. ^ a b c d e "LCDB Data for (1981) Midas". Asteroid Lightcurve Database (LCDB). Retrieved 18 September 2016.
  6. ^ 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. 26: 1003. Bibcode:1995LPI....26.1003M.
  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.
  8. ^ a b 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. 26: 1511. Bibcode:1995LPI....26.1511W.
  9. ^ 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.
  10. ^ 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:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007.
  11. ^ a b c "JPL Close-Approach Data: 1981 Midas (1973 EA)" (2013-12-30 last obs). Retrieved 2014-01-31.
  12. ^ "(1981) Midas Ephemerides for 15 Feb 2018 through 15 Apr 2018". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 2014-01-31.
  13. ^ Ostro, S. J.; Jurgens, R. F.; Rosema, K. D.; Winkler, R.; et al. (October 1991). "Asteroid radar astrometry". Astronomical Journal. 102: 1490–1502. Bibcode:1991AJ....102.1490O. doi:10.1086/115975.
  14. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 18 September 2016.

External linksEdit