951 Gaspra

The asteroid Gaspra was visited by the Galileo probe in 1991 as it flew by on its way to Jupiter. It has half a dozen large concavities which resemble craters, though there is some debate whether these are the result of impacts or whether they are instead facets formed when Gaspra broke off of its parent asteroid. In the weak, lopsided gravity of Gaspra impact craters would naturally take on such flat, lopsided shapes, making this determination difficult.

• Catalogue number: 951
• Dimensions: 19 x 12 x 11 km
• Density: unknown
• Orbit: main belt (Flora family)
• Spectral class: S
• Rotation: 7.04 hours