Engineers say there's a power problem with the just-arrived "Opportunity" rover on Mars, but they don't know how serious it is.
The rover has already beamed back what are thought to the first pictures of Mars bedrock, an exciting development for geologists trying to learn if Mars once had water.
The power glitch involves a heater that keeps turning itself on, even if engineers want it off.
Meanwhile, the prognosis is still iffy for the "Spirit" rover halfway around the Red Planet. NASA is slowly trying to nurse the probe back to life by overcoming computer memory problems. It's also working to make sure the same kind of problems don't crop up on Opportunity.