Recent Water (IMAGE) Brown University Caption The gully system in the Promethei Terra region of Mars appears to have been carved by melt water and may be the most recent period when water was active on the planet. Credit NASA/JPL/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.