Credit: NASA/JPLPublic Domain — NASA Media Usage Guidelines
ASTEROID
Ida
The first asteroid discovered to have a moon — Dactyl — photographed by Galileo in 1993.
Orbits Sun1 moons
About Ida
243 Ida is a main-belt asteroid imaged at close range by NASA’s Galileo spacecraft on 28 August 1993 during its cruise to Jupiter. Galileo’s images revealed Ida’s tiny moon Dactyl (~1.4 km across) — the first confirmed asteroid moon ever observed.
Physical Properties
16 km
4.634 h
0.238
Orbit
Sun
2.862 AU
0.0464
1.133°
4.84 yr
Notable Moons
Dactyl
Moon
Gallery
Hand-picked mission imagery of Ida sourced from NASA and partner archives. Click any photo for full resolution and source attribution.
Asteroid 243 Ida and its moon Dactyl u2014 the first asteroid found to have a moon, from Galileo.
NASA/JPL · Public Domain u2014 NASA Media Usage Guidelines
Imagery on this page is provided by the original mission teams. Full attribution terms: Image Rights & Credits.
