Groovy Phobos (IMAGE) Brown University Caption Much of Phobos' surface is covered with strange linear grooves. New research bolsters that idea the boulders blasted free from Stickney crater (the large depression on the right) carved those iconic grooves. Credit NASA/JPL-Caltech/University of Arizona Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.