http://www.wired.com/news/space/0,2697,66079,00.html?tw=rss.TOP

more reasons i love NASA:

NASA Scientist 1: Hey whats a comet made of under the surface?
NASA Scientist 2: I dunno, lets just chuck a big rock at it and see how big the hole is and what breaks off.
NASA Scientist 1: I’m so on-board with this plan, HIGH FIVE!
[high five between the scientists]

Thats my simulation of how this idea was formed lol.