Sunlight's gentle nudge on asteroids detected 19:00 04 December 03 NewScientist.com news service Astronomers have detected the delicate force of sunlight on an asteroid's orbit for the first time. The long-predicted effect has been blamed for propelling some asteroid fragments from the Solar System's main asteroid belt into the region near Earth, where they can threaten the planet. But its subtle action on asteroid orbits has been difficult to measure with optical telescopes. Instead, Steve Chesley, Steve Ostro and colleagues at NASA's Jet Propulsion Lab in Pasadena, California, used the radar range finder at Arecibo in Puerto Rico. They used...