Big asteroid could pose threat to Earth in 2040

Scientists are keeping a close eye on a big asteroid that may pose an impact threat to Earth in a few decades.

The space rock, which is called 2011 AG5, is about 460 feet (140 meters) wide. It may come close enough to Earth in 2040 that some researchers are calling for a discussion about how to deflect it.

Read more: http://www.foxnews.com/scitech/2012/02/27/big-asteroid-could-pose-threat-to-earth-in-2040/