Mars Rover Finds Weird Rocks, Hits 20-Km Marker

With new software that allows Opportunity to photograph rocks and other aspects of the Martian terrain and decide for itself what is worth closer inspection, the rover took an up-close look at a few rocks ejected by the impact that created Concepción.
What Opportunity has seen are chunks of the same type of bedrock it has seen at hundreds of locations since landing in January 2004: soft, sulfate-rich sandstone holding harder peppercorn-size dark spheres like berries in a muffin. The little spheres, rich in iron, gained the nickname “blueberries.” But these rocks have some unusual twists as well.
“It was clear from the images that Opportunity took on the approach to Concepción that there was strange stuff on lots of the rocks near the crater,” said Steve Squyres of Cornell University in Ithaca, N.Y., principal investigator for Opportunity and its twin rover, Spirit. “There’s dark, grayish material coating faces of the rocks and filling fractures in them. At least part of it is composed of blueberries jammed together as close as you could pack them. We’ve never seen anything like this before.”