Deep Impact comet strike. Explosion on the surface of the nucleus (grey) of the comet 9P/Tempel 1, 16 seconds after the Deep Impact impactor struck it. The Deep Impact spacecraft launched a 360-kilogram impactor at the comet, and it successfully struck it at over ten kilometres per second on 4th July 2005. The impact caused the ejection of a large amount of interior material. The mission was launched on 12 January 2005. It was designed to study the composition of a comet, as comets are relics from the formation of the solar system. As such, they can provide much information about its history and formation. The image was captured by the Deep Impact spacecraft.