NASA has released color photographs of a Martian rock formation that could have been carved out by water.
The photos come from the panoramic camera on the rover Opportunity. The detail of horizontally striped and fractured areas of bedrock is described as "pretty phenomenal" by scientist Jim Bell, who's in charge of the camera.
The scientific instruments aboard Opportunity should allow it to reconstruct the geologic events that created the layers.
Among the possibilities, Bell says, are lava flows and sediment deposits.
Meanwhile, on the other side of Mars, Opportunity's twin, Spirit, continues its recovery from what's believed to have been a software problem. If all goes well, a mission manager says, Spirit could resume collecting data next week.