"It figures that if there was only one rock for what seems like miles in every direction, we'd find a way to hit it," said Steven Squyres, the principal investigator for the Mars Exploration Rover mission. He was describing an unusual object, later called "Bounce Rock" that Spirit bounced off of during its airbag landing. Scientists were split over whether this unusual object was a rock at all - they thought it could have been a piece of Spirit's landing equipment, or maybe even a meteorite. But when Spirit finally analyzed it up close, the case was closed: it's a rock that was probably blasted out of an impact crater 50 km away.