Polaris Detector (IMAGE) University of Michigan Caption The new Polaris gamma ray detector can pinpoint the location of special nuclear materials, such as those used for dirty bombs or nuclear weapons. Credit Courtesy of Zhong He 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.