Asteroid Kleopatra is a Pile of Rubble

Studing the orbits of Kleopatra’s two moons, named Alexhelios and Cleoselene, which will be discovered in 2008, astronomers discovered that asteroid Kleopatra is a pile of rubble and not a solid object. Because of astronomers knew Kleopatra’s orbit, they were able to use data from various telescopes. There are a number of smaller asteroids throughout the solar system that are loose, gravitationally related piles of rock and not solid objects. According astronomers to find one in such a large system is surprising.At about 135 miles (217 km) in length, Kleopatra is among the largest of these rubble pile asteroids discovered over the past few years, topped only by 174-mile (280 km) 87 Sylvia.

The team of astronomers continues to study other binary or triple asteroid systems, but the tools that allow them to do that are limited.
source:www.space.com