GEMS (IMAGE) NASA/Goddard Space Flight Center Caption GEMS, the Gravity and Extreme Magnetism Small Explorer, will detect polarized X-rays from supernova remnants, neutron stars and black holes. Polarized X-rays carry information about the structure of cosmic sources that is not available in any other way. Credit NASA/GEMS/Barbara Talbott 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.