4486 Mithra

4486 Mithra (prov. designation: Template:Mp), is an eccentric asteroid and suspected contact-binary, classified as near-Earth object and potentially hazardous asteroid, approximately 2 kilometers in diameter. It belongs to the Apollo group of asteroids and is a relatively slow rotator.

The asteroid was discovered on 22 September 1987, by Belgian astronomer Eric Elst and Bulgarian astronomer Vladimir Shkodrov at Rozhen Observatory, in the Smolyan Province of Bulgaria.<ref name="MPC-Mithra" /> It was named after the Indo-Iranian divinity Mithra.<ref name="springer" />

Orbit and classification

Mithra orbits the Sun at a distance of 0.7–3.7 AU once every 3 years and 3 months (1,192 days). Its orbit has an eccentricity of 0.66 and an inclination of 3° with respect to the ecliptic.<ref name="jpldata" /> In 1974, Mithra was first identified as Template:Mp at Crimea–Nauchnij. The body's observation arc begins 8 months prior to its official discovery observation, with a precovery taken at the Japanese Kiso Observatory in January 1987.<ref name="MPC-Mithra" />

Close approaches

As a potentially hazardous asteroid, it has a low minimum orbit intersection distance with Earth of Template:Convert.<ref name="jpldata" /> On 14 August 2000, it passed Template:Convert from Earth.<ref name="jpldata" />

Earth Approach on 11 April 2023<ref name=jpldata/>

Date	JPL Horizons nominal geocentric distance (AU)	uncertainty region (3-sigma)
2023-Apr-11 16:49	Template:Convert<ref name="jpldata"/>	±Template:Val<ref name="CA2023"/>

Venus Approach on 4 November 2150<ref name=jpldata/>

Date	JPL Horizons nominal geocentric distance (AU)	uncertainty region (3-sigma)
2150-Nov-04 17:06 ± 00:18	Template:Convert<ref name="jpldata"/>	±Template:Val<ref name="Venus2050"/>

Physical characteristics

Rotation period and shape

Radar imaging using a delay-Doppler technique at the Arecibo and Goldstone observatories rendered a rotation period of Template:Val hours.<ref name="Brozovic-2010" /> Based on the radar analysis, Mithra is also a strong candidate for a contact binary, which is composed of two distinct lobes in mutual contact, held together by their weak gravitational attraction. They typically show a bifurcated, dumbbell-like shape (also see 4769 Castalia).<ref name="Brozovic-2010" /><ref name="Binary" /> A large number of near-Earth objects are believed to be contact-binaries.<ref name="Busch-2012" />

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Mithra measures 1.85 kilometers in diameter and its surface has a high albedo of 0.297, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 2.25 kilometer with an absolute magnitude of 15.6.<ref name="WISE" /><ref name="Mainzer-2011" /><ref name="lcdb" />

Naming

This minor planet was named after Mithra (also see Mitra), deity in the proto-Indo-Iranian religion. The mystery religion of Mithraism was practiced in the Roman Empire between the 1st and 4th century. Considered to be a rival of early Christianity, both religions shared similar characteristics such as elevation and the ritual of baptism. In the Hellenistic world, Mithra was conflated with Apollo. The asteroid 1862 Apollo is the namesake of this asteroid's orbital group.<ref name="springer" /> The approved naming citation was published by the Minor Planet Center on 5 September 1990 (Template:Small).<ref name="MPC-Circulars-Archive" />

External links

• (4486) Mithra at NeoDys, Near Earth ObjectsTemplate:Snd Dynamic Site
• Radar observations and a physical model of contact binary Asteroid 4486 MithraTemplate:Snd Science Direct
• 3D Model Rotating image of the asteroid
• Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdRTemplate:Snd Observatoire de Genève, Raoul Behrend
• Template:NeoDys
• Template:ESA-SSA
• Template:JPL small body