IMPACTOR Strikes Comet

On the 4th of July, 2005, an 820-pound copper projectile called IMPACTOR struck a comet named Tempel 1. 

Meanwhile, a nearby space probe—"Deep Impact"—monitored (and photographed) what happened during the collision.  This NASA animation—by Maas Digital—recreates the events.

Among other things, the purpose of the NASA mission was to examine whatever materials were dislodged by the impact—and—to observe the surface of the comet after the collision. The "Deep Impact" mission had been launched into space from Cape Canaveral, via a Delta II rocket, seven months earlier (on January 12, 2005).

Scientists were surprised to learn that IMPACTOR "excavated so much material that the underlying crater was hidden from view."  As a result, "Deep Impact's cameras were unable to see through the enormous cloud of dust the impactor had stirred up."

NASA has sent another mission, referred to as Stardust-NExT, to further explore what Deep Impact set in motion.  Among other things, scientists want to know why Tempel 1 has layers which resemble stacks of pancakes.