TheSync writes "Eurekalert reports on 'definitive evidence' for an ancient water lake on Mars. A UC Boulder research team has discovered evidence of a shoreline on Mars of a 3 billion year-old lake 80 square miles in area and 1,500 feet deep (roughly the equivalent of Lake Champlain). Images came from the HiRISE instrument on NASA's Mars Reconnaissance Orbiter. Water carved a 30-mile-long canyon that opened up into a valley and forming a large delta during a time when Mars is generally believed to have been cold and dry. The lack of additional, lower shorelines, shows that the lake dried up very quickly. Of particular interest are the deltas adjacent to the lake. On Earth, deltas rapidly bury organic carbon and other biomarkers of life, making the Martian lake bed and delta a prime target for future searches for past life on the planet."