Tempel 1 is hit by the Deep Impact missile

NASA visits comet blasted by missile

A NASA spacecraft is homing in today to check up on a comet that another probe blasted with a missile. Space scientists want to see how the cosmic iceball, called Tempel 1, had changed.

Vein of martian clay and carbonate

Mars meteorites held liquid water

Space scientists have found evidence of liquid water on Mars caused by an asteroid impact in rare martian meteorites that crashed to Earth.