Artist's concept showing the large 270-km asteroid Sylvia surrounded by its two satellites, Romulus and Remus. The primary asteroid of the system may have a dense, regularly-shaped core, surrounded by... more 
Artist's concept showing the large 270-km asteroid Sylvia surrounded by its two satellites, Romulus and Remus. The primary asteroid of the system may have a dense, regularly-shaped core, surrounded by fluffy material. The two moons are strongly less 
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SPACE.com | Photo By Danielle Futselaar/SETI Institute
Tue, Oct 8, 2013 7:40 AM EDT