I was reading up on the asteroid that has a chance of hitting us in twenty years and its incredible. this asteroid will arrive in 2027, 2039 and 2044 again, and possible more after that. In as it comes by us each time our gravitational pull could move it just enough to hit us..and if that were the case it would be game over.
as of now the chances it will hit are something like 1 in 3million the first time and then 1 in 500k the third time. However it is suppose to pass between the earth and our communications satellites!! Unreal.
there was also a neat history channel show in this a few days ago which might come on again if youre lucky.
more info:
http://abob.libs.uga.edu/bobk/ccc/cc052599.html