Nightly News | February 11, 2013
>>> four days remaining until the earth has a very close call with an astroid. it's 150 feet wide. it will pass only 17,000 miles above us. that is closer to us than satellites orbit. and there are about 3,000 of those up there. it's traveling eight times the speed of a gunshot. astronomers are all over it. it will go by before we know it.