In a bold example of astronomical recycling, NASA decided to give the Stardust probe a new purpose in life. Stardust gained its fame for capturing material from the tail of the comet Wild 2 back in 2004 and dropping its sample capsule to Earth in 2006. But the probe itself remained in space, and in February its detectors will be turned toward a new target.

The new subject, the comet Tempel 1 (pictured), was itself part of a previous investigation. In 2005, the Deep Impact mission set out to characterize the inside of the comet by smashing into it with an 800-pound chunk of copper. Stardust will give us an important, and cheap, second look at the crater formed by Deep Impact when it flies by Tempel 1. This will be particularly useful because the hit by Deep Impact tossed up a cloud of dust that prevented that spacecraft from getting a good look at the damage.