Key facts
- Category
- Asteroids
- Object class
- S-type main-belt asteroid
- Mass
- ~10 trillion metric tons
- Scale fact
- 18.2 kmmaximum extent
- Estimated age
- ~4.5 billion years
- Composition
- Silicate rock with metal
18.2 kmmaximum extent
Details
951 Gaspra is the first asteroid ever seen up close, photographed by NASA's Galileo spacecraft in 1991 on its way to Jupiter. The flyby passed about 1,600 kilometers away and revealed an irregular, cratered S-type body about 18 kilometers long.
Galileo passed about 1,600 kilometers from Gaspra on 29 October 1991 and returned the first close images of an asteroid. They resolved an irregular body with craters, grooves and a loose surface layer.
Key facts
Links
Size neighbors
On the logarithmic size axis, 951 Gaspra falls between Deimos and Crab Pulsar. Compared below with other objects classed as S-type main-belt asteroid.
Sources
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, write to hello@scaleofspace.org.
Continue with nearby objects or open the full scale.
About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.