Peanut-shaped asteroid is denser on one end

Science : New analysis of the small, near-Earth asteroid Itokawa shows that one end of the peanut-shaped body is significantly denser than the other. For more than a decade, the asteroid has been studied by Earth-based telescopes, and in 2005 Japan’s Habayusa spacecraft collected data on the asteroid’s size, shape, and composition. In a recent study published in Astronomy and Astrophysics, Stephen Lowry of the University of Kent and colleagues discuss the object’s rotation, from which they determined that its center of mass was 21 m closer to the smaller end than expected. That observation leads them to believe that the smaller end could be at least 1.6 times denser than the larger end. The astronomers propose that Itokawa is composed of two different types of material, or possibly two different asteroids, stuck together. Furthermore, they have found that Itokawa’s spin is accelerating.