"Infrared detectors on Spitzer found the traces of rocky rubble and re-frozen lava around a young star, called HD 172555, still in the early stages of planet formation. The system is about 100 light-years from Earth. One light-year is the distance light travels in a year (about six trillion miles).
A similar fender-bender is thought to have formed Earth's moon more than 4 billion years ago, when a body the size of Mars rammed into Earth.
"The collision that formed our moon would have been tremendous, enough to melt the surface of Earth," said co-author Geoff Bryden of NASA's Jet Propulsion Laboratory in California. "Debris from the collision most likely settled into a disk around Earth that eventually coalesced to make the moon. This is about the same scale of impact we're seeing with Spitzer - we don't know if a moon will form or not, but we know a large rocky body's surface was red hot, warped and melted." In fact, such violent encounters seem to have been common in our own solar system's early history. For example, giant impacts are thought to have stripped Mercury of its outer crust, tipped Uranus on its side, and spun Venus backward.
http://www.foxnews.com/story/0,2933,538815,00.html?test=latestnews
Someday humans might be living in that solar system.