Telescope lets astronomers study internal 'anatomy' of an asteroid

European astronomers say a telescope in Chile has found the first evidence asteroids can have a highly varied internal structure. The European Southern Observatory's New Technology Telescope at the La Silla Observatory, making precise measurements of the asteroid Itokawa, found different parts of the asteroid have different densities, a release from ESA headquarters in Germany reported Wednesday. Determining the interior makeup of asteroids may shed light on what happens when bodies collide in the solar system and provide clues about how planets form, astronomers said. Itokawa is an intriguing subject with its strange peanut shape, as revealed by the Japanese spacecraft Hayabusa in 2005. Observations of variations in its brightness as it rotates allowed astronomers to deduce the asteroid's spin period very accurately. When combined with knowledge of the asteroid's shape, this allowed them to determine its interior makeup, revealing the complexity within its core for the first time. "This is the first time we have ever been able to to determine what it is like inside an asteroid," Stephen Lowry of Britain's University of Kent said. "We can see that Itokawa has a highly varied structure -- this finding is a significant step forward in our understanding of rocky bodies in the Solar System." The glimpse into the diverse innards of Itokawa has led to much speculation regarding its formation, with some astronomers theorizing it formed from the two components of a double asteroid after they bumped together and merged.