(243) Ida
Asteroid (243) Ida |
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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 |
eccentricity | 0.042 |
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 |
Physical Properties | |
Medium diameter | 59.8 × 25.4 × 18.6 km |
Dimensions | 4.12 x 10 16 | kg
Albedo | 0.2383 |
Medium density | 2.5 g / cm³ |
Rotation period | 4 h 38 min |
Absolute brightness | 9.94 mag |
Spectral class | S. |
history | |
Explorer | Johann Palisa |
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. |
(243) Ida is an asteroid of the main asteroid belt that was discovered on September 29, 1884 by Johann Palisa at the Vienna University Observatory.
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 .
It was also shown that Ida is orbited by a small natural satellite . This moon, only 1.4 km in size, was named Dactyl and was the first asteroid moon to be observed.