The golf cart-size Spirit rover is off and rolling around Mars trying to figure out if it landed in a sort of ancient water hazard. Its twin, Opportunity, is on course to plop down Saturday on the opposite side of the planet and do the same. Mission scientists are so giddy you’d think they just shot a hole-in-one.
But the Mars Exploration Rovers Mission, or MER as some call it, has nothing to do with golf. The mission team is excited because they finally get to take a shot at what they’ve practiced for years: science on the red planet.