Gaspra

Definition

(951) Gaspra is a main-belt asteroid named after a Crimean town located on the Black Sea. It was the first asteroid to be visited by spacecraft, when the NASA Galileo probe approached it on its course to Jupiter. The analysis of the Galileo images revealed a body approximately 18 × 10 × 9 km in size, with an irregular shape and with a comparatively young surface age between 30,000 and 300,000 years. The body probably originated in a disruptive collision that created the Flora asteroid family, which is believed to comprise about 10³ objects. Gaspra is classified as an S-type asteroid, and its surface displays the spectral signature of mafic minerals. Galileo images confirmed the presence of subtle color variations across its surface, which had been previously detected by ground-based observations and which are interpreted as the manifestation of downslope movement of regolith.