951 Gaspra
 NASA image of 951 Gaspra | |
|---|---|
| Orbital characteristics | |
| Orbit type | (Minor planet>Floras family) |
| Semimajor axis | AU |
| Eccentricity | 0.17331 |
| Orbital period | 3.29 y |
| Inclination | 4.10284° |
| Physical characteristics | |
| Diameter | km |
| Mass | 16 kilogram>kg |
| Density | g/cm³ |
| Rotation period | 7 h 5 min 30 s |
| Spectral class | S |
| Albedo | 0.22 |
| History | |
| Discoverer | G. N. Neujmin, 1916 |
951 Gaspra is an S-type asteroid that orbits in the inner edge of the asteroid belt. Gaspra was the first asteroid ever closely approached when it was visited by the Galileo probe on October 29, 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.
Gaspra was discovered by Russian astronomer G. N. Neujmin in 1916. Neujmin named Gaspra after a Black Sea retreat that was visited by his contemporaries such as Gorky and Tolstoy.