Io (minor planet designation: 85 Io is carbonaceous asteroid from the central region of the asteroid belt, approximately 170 kilometers in diameter.
It is an identified Eunomian interloper.
Discovery and naming
It was discovered by C. H. F. Peters on September 19, 1865, and named after Io, a lover of Zeus in Greek mythology.
Io is also the name of the volcanic satellite of Jupiter.
With a two-digit number and a two-letter name, 85 Io has the shortest designation of all minor planets.
Orbit and physical characteristics
Io is a retrograde rotator, with its pole pointing towards one of ecliptic coordinates (β, λ) = (-45°, 105°) or (-15°, 295°) with a 10° uncertainty.
This gives an axial tilt of about 125° or 115°, respectively.
Its shape is quite regular.
In the SMASS classification, Io is a carbonaceous C-type asteroid, which means that it is probably a primitive body composed of carbonates.
Like 141 Lumen it is an interloper that orbits within the Eunomia asteroid family but it is not related to the shattered parent body.
An Ionian diameter of 178 kilometres was measured from an occultation of a star on December 10, 1995.
Another asteroid occultation of Io (magnitude 13.2) occurred on March 12, 2009, from the eastern United States, with the star 2UCAC 35694429 (magnitude 13.8).http://www.asteroidoccultation.com/2009_03/0312_85_20455.htm
See also
List of Solar System objects by size
References
External links
Shapes and rotational properties of thirty asteroids from photometric data, Torppa (2003)
000085 Category:Discoveries by Christian Peters Category:Minor planets named from Greek mythology Category:Named minor planets 000085 000085 000085 18650919
