Heat-Seeking Telescope Tracks Deadly Space Rocks

Scientists estimate there are as many as 6,200 near-Earth asteroids that could slam into us one day. Unfortunately, they're hard to spot -- we've had to look for them based on the minuscule amounts of light they reflect toward us. But recently researchers at NASA's Jet Propulsion Laboratory have turned to a space telescope known as WISE (Wide-field Infrared Survey Explorer) to get a better picture based on the heat they produce. The result is the most detailed map we've ever had of the location and orbital path of potentially hazardous asteroids.