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243 Ida is a Koronis asteroid orbiting the Sun between Mars and Jupiter:
orbit: 270,000,000 km from the Sun (average)
size: 58x23 km
Ida was a nymph who raised the infant Zeus (Jupiter). Ida is also the name of a mountain on the island of Crete, the site of a classic shrine and the cave where Zeus was said to have been reared.
The second of only three asteroids that have so far been observed close-up, Ida was encountered Aug. 28, 1993, by the Galileo spacecraft on its way to Jupiter.
Ida has a
satellite! (It's the small spot to the right 
in the picture above.) It is the first natural satellite of an
asteroid ever discovered. It received the name Dactyl (and the
permanent designation "(243) Ida I") in September 1994. The name is
derived from the Dactyli, a group of mythological beings who lived on
Mt. Ida and protected the infant Zeus. Other accounts are that the
Dactyli are the children of the nymph Ida and Zeus.
Dactyl (right) is about 1.6 x 1.2 km, surprisingly round for such a small body. It orbits Ida at approximately 90 km.
Interestingly,
while the spectra of Ida and Dactyl are very similar they are
nevertheless distinctly different; Dactyl is not simply a chunk of
Ida. It is thought that the binary system may have formed during the
collision and breakup that created the Koronis family.
The surfaces of Ida and Dactyl are heavily cratered and therefore apparently quite old. But dynamical calculations indicate that the whole Koronis family is relatively young. Such calculations also indicate that objects the size of Dactyl may not be to survive for more than 100 million years or so. Perhaps the heavy cratering took place at the time of the breakup that created the Koronis family rather than the 4 billion years ago as is usually the case for such surfaces.
... Sun ... Small
Bodies ... Gaspra ... Ida ... Mathilde
... 
