Consider it the first interplanetary photobomb. On July 19th, NASA's Cassini spacecraft will photograph Earth through the rings of Saturn--and NASA wants you to jump into the shot. "Cassini has photographed Earth before, but this will be the first time Earthlings know in advance their picture will be taken from a billion miles away," says Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, CA. "We hope that people around the world will go outside to wave at Saturn while the photo-shoot is underway."