|Asteroid Ida with moon Dactyl|
|Properties of the orbit ( animation )|
|Orbit type||Outer main belt|
|Asteroid family||Koronis family|
|Major semi-axis||2,862 AU|
|Perihelion - aphelion||2.743 AU - 2.981 AU|
|Inclination of the orbit plane||1.1 °|
|Length of the ascending node||324 °|
|Argument of the periapsis||110 °|
|Time of passage of the perihelion||March 9, 2011|
|Sidereal period||4 a 308 d|
|Mean orbital velocity||17.6 km / s|
|Medium diameter||59.8 × 25.4 × 18.6 km|
|Dimensions||4.12 x 10 16kg|
|Medium density||2.5 g / cm³|
|Rotation period||4 h 38 min|
|Absolute brightness||9.94 mag|
|Date of discovery||September 29, 1884|
|Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.|
The asteroid was named after the nymph Ida from Greek mythology.
Ida is an irregularly shaped, elongated body with a mean diameter of 31.4 kilometers. It has a light, silicate-rich surface.
On August 28, 1993, the Galileo space probe passed the asteroid at a distance of 10,500 km and sent CCD images to Earth. The images show that the celestial body is covered by impact craters . Large parts of the asteroid are covered by a layer of dust, the regolith .