http://en.wikipedia.org/wiki/Edmond_Halley
http://delphes.net/messier/xtra/Bios/halley.html
_ Bill Nye - Greatest Discoveries - 1: Astronomy 1/5
http://www.youtube.com/watch?v=-V9OzCqR01g
_ Silent Drifting
http://www.youtube.com/watch?v=crdOQb385u4
