Across the globe, technology that is designed to generate solar energy could potentially be employed for yet another planet-saving enterprise: Asteroid detection. One scientist at Sandia National Labs has started to get the ball rolling on a theory using a large-scale mirror, and a bit of ingenuity and hope. Sitting just south of Albuquerque is a field of more than 200 large-scale mirrors. These heliostats focus the immense power of the sun on to a 200-foot tower, collecting as much as a million watts of power during the day, but at night, they don’t have a job — they’re just...