Deep Impact

Deep Impact was a NASA space probe designed to study the interior composition of the comet Tempel 1 (9P/Tempel), by releasing an impactor into the comet. At 05:52 UTC on July 4, 2005, the Impactor successfully collided with the comet's nucleus. The impact excavated debris from the interior of the nucleus, forming an impact crater. Photographs taken by the spacecraft showed the comet to be dustier and less icy than expected. The impact generated an unexpectedly large and bright dust cloud, obscuring the view of the impact crater.