Astronomers have for awhile now known that there is the potential for an asteroid to collide with Earth and wreak havoc on our planet. They know it has happened before. Now, a smallish asteroid called Apophis has been identified as a possible threat to Earth in 2036. While it likely will miss Earth, further refinements to the modeling being done are necessary to determine for sure.
This is where science fiction meets science, however.
[NASA] is drawing up plans to land an astronaut on an asteroid hurtling through space at more than 30,000 mph. It wants to know whether humans could master techniques needed to deflect such a doomsday object when it is eventually identified. The proposals are at an early stage, and a spacecraft needed just to send an astronaut that far into space exists only on the drawing board, but they are deadly serious.Bruce Willis, are you available?