The asteroid Ida orbits the Sun between the orbits of Mars and Jupiter. It takes about 4.8 years to complete an orbit. Ida has a moon named Dactyl, official designation (243) Ida I Dactyl, discovered in images taken by the Galileo spacecraft during its flyby in 1993. These images provided the first direct confirmation of an asteroid moon. Dactyl is heavily cratered, like Ida, and consists of similar materials, suggesting they are fragments of the same parent body. Ida is the dot on the right side of the image above. The image on the left is our best closeup of Dactyl to date. Dactyl is about 1.6 x 1.4 x 1.2 km across.
Image Credits: NASA