Mars lander is a "go"

"Opportunity" finally got off the ground late Monday, following its twin spacecraft "Spirit" on a trajectory to Mars. It'll be a six-month wait before we hear more, so study up on areology (that's Mars geology) here in the meantime. Learn about shergottites—Mars rocks like this one, found in Oman.

About Space Guide Nick Greene covered the launch. Up-to-date mission news is at NASA's Mars Exploration Rover Mission site.