1981 Midas

1981 Midas, provisional designation Template:Mp, is a vestoid asteroid, classified as a near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter.<ref name="jpldata"/>

It was discovered on 6 March 1973 by American astronomer Charles Kowal at Palomar Observatory in San Diego County, California.<ref name="MPC-Midas" /> It was named after King Midas from Greek mythology.<ref name="springer" />

Classification and orbit

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.<ref name="jpldata"/>

Midas has a low minimum orbit intersection distance with Earth of Template:Convert, which corresponds to 1.5 lunar distance (Earth–Moon distance). However, it does not pose an impact risk for the foreseeable future. On 19 March 1947 it passed Template:Convert from Earth.<ref name=jpl-close/> The last notable close approach was on 21 March 2018 passing Template:Convert from Earth<ref name=jpl-close/> and shining at an apparent magnitude of +12.4.<ref name="NEODyS2018"/> The next notable close approach will be on 14 September 2032 passing slightly closer at Template:Convert from Earth.<ref name=jpl-close/> As no precoveries are known, the asteroid's observation arc begins with its discovery observation at Palomar in 1973.<ref name="MPC-Midas" />

With a semi-major axis of 1.78 AU, when 1 AU from the Sun (and passing Earth's orbit) the asteroid is moving at 35.7 km/s with respect to the Sun.Template:Efn For comparison Earth orbits the Sun at 30 km/s.

Physical characteristics

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 (Template:Small).<ref name="Torppa-2005" /><ref name="Mottola-1995a" /><ref name="Wisniewski-1997" />

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,<ref name="AKARI" /> 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.<ref name="lcdb" />

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.<ref name="Ostro1991" />

Naming

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.<ref name="springer" /> The official Template:MoMP was published by the Minor Planet Center on 15 October 1977 (Template:Small).<ref name="DoMP-Circular-dates" />

External links

• IAUC 2816 (13 August 1975)Template:Snd IAUC 2890 (29 December 1975)Template:Snd IAUC 2979 (26 July 1976)
• NeoDys Close Approaches from 1950 to 2100
• Dictionary of Minor Planet Names, Google books
• Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
• Asteroids and comets rotation curves, CdRTemplate:Snd Observatoire de Genève, Raoul Behrend
• Asteroid Hazards, Part 1: What Makes an Asteroid a Hazard?Template:Snd Minor Planet Center on YouTube
• Template:NeoDys
• Template:ESA-SSA
• Template:JPL small body