The asteroid Ida
and its newly-discovered moon, Dactyl. The image was taken by NASA's
Galileo spacecraft, about 14 minutes before its closest approach to
the asteroid on August 28, 1993. Ida appears to be about 52 km (32 mi)
in length and is irregularly shaped. This view shows numerous craters,
including many degraded craters, indicating Ida's surface is older than
previously thought. Photo: NASA/JPL.