Shoemaker-Levy 9 hits Jupiter

The comet Shoemaker-Levy 9 struck Jupiter on 16 July 1994. Clearly visible through telescopes on Earth, the impact was the first time a collision between two objects in the Solar System had been seen. Researchers believe that the planets formed through a series of such collisions. This clip features commentary by Dr David Levy, co-discoverer of Shoemaker-Levy 9.