Everyone knows that eight planets orbit the sun. But thousands of other objects, including icy comets and football field-sized asteroids, are also zooming around our solar system. And some of them could be on a collision course with Earth. QUEST explores how these Near Earth Objects are being tracked and what scientists are saying should be done to prevent a deadly impact.
Update: A 150-foot asteroid hurtled through Earth's backyard Friday, coming within an incredible 17,150 miles and making the closest known flyby for a rock of its size. Get more info at KQED News.