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Click on an object in the solar system or choose from the list at left to learn more |
The Arecibo Planetary Radar discovered that near-Earth Asteroid 2001 SN263 is a triple asteroid system.
The Arecibo Asteroid Dynamics Workshop was held 2003 Feb 2-4 at Arecibo Observatory. Click Here for the workshop web site.
2000 DP107 was the first asteroid identified by radar as a binary system. The primary is roughly spherical with a diameter of 800 meters (a half mile) and the smaller secondary, which orbits it in 1.8 days, is about 300 meters (1000 feet).
The primary has a low density of 1.7 and is assumed to be a "rubble pile" of rocks and voids. It is spinning at a rate near the breakup point for strengthless bodies, and therefore any slight gravitational disturbance can pull it apart. Probably an encounter with the gravity of a planet created the binary by pulling apart the primary.
Four more binary systems have been discovered by radar among the near-Earth asteroids, making one of every 6 a binary.
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The illuminated front of a roughly spherical primary is visible, as well as a secondary at different phases of the orbital cycle. In this image the secondary appears much smaller than the primary because its spin rate is lower. The actual size ratio is 8 to 3. Also, the orbit appears elliptical in this image but it is circular in space. |
More on 2000 DP107:
Margot web page ,
Klet Observatory optical data ,
IAU Circular #7496 ,
IAU Circular #7503 ,
Table from NeoDys,
Orbit diagram from JPL
Last modified by Alice 23 apr 02