NASA's Chandra releases timelapse movies of Crab Nebula and Cassiopeia A

New movies of two of the most famous objects in the sky--the Crab Nebula and Cassiopeia A--are being released from NASA's Chandra X-ray Observatory. Each includes X-ray data collected by Chandra over about two decades. They show dramatic changes in the debris and radiation remaining after the explosion of two massive stars in our galaxy.