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Gaspra

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ASTEROID

Gaspra

The first asteroid ever visited by a spacecraft — Galileo flyby, October 1991.

Orbits Sun

Physical Properties

6 km
7.042 h
0.22

Orbit

Sun
2.21 AU
0.173
4.1°
3.29 yr

Sources & Further Reading

Numerical values (radius, mass, orbital elements, temperatures) are drawn from NASA NSSDC Planetary Fact Sheets, JPL Horizons, and the JPL Small-Body Database. Last refreshed: 2026-04-18 18:19:27.

951 Gaspra is an S-type main-belt asteroid that on 29 October 1991 became the first asteroid ever visited by a spacecraft, when NASA’s Galileo flew past it on its way to Jupiter.