Asteroid Ida and its Satellite Dactyl in Enhanced Color
During its examination of the asteroid Ida, NASA's Galileo spacecraft returned images of a second object, Dactyl--the first confirmed satellite or moon of an asteroid; the much smaller moon is visible to the right of Ida.
This picture shows the asteroids Ida (left) and Gaspra (right) to the same scale. These images were taken by NASA's Galileo spacecraft while enroute to Jupiter. Gaspra was imaged on October 29, 1991 at a range of 3,300 miles (5,300 km).
This view of the asteroid 243 Ida is a mosaic of five image frames acquired by NASA's Galileo spacecraft's solid-state imaging system at ranges of 3,057 to 3,821 kilometers (1,900 to 2,375 miles) on August 28, 1993.
This is the first full picture showing both asteroid 243 Ida and its newly discovered moon to be transmitted to Earth NASA's Galileo spacecraft -- the first conclusive evidence that natural satellites of asteroids exist.