WELL, THIS ISN'T GOOD

NASA's Spirit rover stopped transmitting data from Mars for more than 24 hours, mission managers said Thursday, calling it an "extremely serious anomaly."

NASA last heard from Spirit early Wednesday. Since then, it has returned just random, meaningless radio noise — and only then sporadically, scientists said. Initially, the scientists said they believed weather problems on Earth caused the glitch. They now said they believe the rover was experiencing hardware or software problems.

"This is a serious problem. This is an extremely serious anomaly," project manager Pete Theisinger said.

Spirit is one half of a $820 million mission. Its twin, Opportunity, is scheduled to land on Mars on Saturday.

NASA last heard from Spirit as it prepared to continue its work examining its first rock, just a few yards from its lander.

Serious bummer