Mars Exploration Rover project manager Pete Theisinger (R) gestures two for two as he celebrates the landing of the second rover Opportunity with Jet Propulsion Laboratory Director Charles Elachi (L) and NASA Administrator Sean O'Keefe, Jan. 24, 2004 at the Jet Propulsion Laboratory in Pasadena, California. Opportunity joins its sister rover Spirit on the surface of Mars. The unmanned, six-wheeled rover landed at 9:05 p.m. PST in Meridiani Planum, NASA said. (AP PHOTO/Damian Davarganes)
