Strangely shaped depressions on Mars could be new places to look for signs of life on the Red Planet, according to a study at the University of Texas - Austin. The depressions were probably formed by volcanos beneath glaciers and could provide a warm, chemical-rich environment well suited for microbial life. These are similar in many ways to "ice cauldrons" on Earth -- formations found in Iceland and Greenland that are made by volcanos erupting under sheets of ice.