4486 Mithra

4486 Mithra, provisional designation 1987 SB, is a highly eccentric asteroid, classified as a near-Earth and potentially hazardous object. The suspected contact-binary asteroid belongs to the group of Apollo asteroids and measures about 2 kilometers in diameter. It 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.

The S-type asteroid orbits the Sun at a distance of 0.7–3.7 AU once every 3 years and 3 months (1,191 days). Its orbit is tilted by 3 degrees to the plane of the ecliptic and shows an outstandingly high eccentricity of 0.66. The potentially hazardous asteroid has an Earth minimum orbit intersection distance of 0.0462 AU. On 14 August 2000, it passed 0.0465 AU (6,960,000 km) from Earth.

Radar imaging using a delay-Doppler technique at the Arecibo and Goldstone observatories rendered a rotation period of 7001675000000000000♠67.5±6 hours. Based on the radar analysis, the asteroid 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). A large number of near-Earth objects are believe to be contact-binaries.