NASA Testing Defense System as Asteroid Heads Near Earth

NASA is planning to test its system for defending Earth against threats from space as a small asteroid starts to approach Earth this summer. The asteroid's trajectory will bring it near our planet in October.

Scientists say the asteroid could come as close as 4,000 miles or as far as 170,000 miles away, which is about two-thirds of the distance from Earth to the moon.

NASA will use its international network of observatories to follow the space rock and learn more about it.

The space agency is hoping to learn how well it can track future asteroid approaches so they can be detected before they become a serious threat to earth.

"We are adding in another layer of effort, using this asteroid flyby to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to finding a potential real asteroid threat," said Michael Kelley, NASA's lead for this particular campaign.

The asteroid named TC4 is on the smaller side, estimated between 30 and 100 feet in size.

"Asteroid 2012 TC4 may be slightly larger than the space rock that hit Earth's atmosphere near Chelyabinsk, Russia, in February 2013," NASA reports.

NASA's website states that its "Planetary Defense Coordination Office is responsible for finding, tracking and characterizing potentially hazardous asteroids and comets coming near Earth, issuing warnings about possible impacts, and assisting coordination of U.S. government response planning, should there be an actual impact threat."