Martian Bomb Sag (IMAGE) Georgia Institute of Technology Caption This bomb sag on the surface of Mars was created during a volcanic blast approximately 3.5 billion years ago. Assistant professor Josef Dufek has replicated the sag in his lab while studying the possibility of water and atmospheric conditions of early Mars. Credit NASA/JPL 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.