Puppis A supernova gas cloud

The NASA composite image captured by NASA’s Spitzer Space Telescope and Chandra X-Ray Observatory, and the European Space Agency's XMM-Newton shows a cloud of gas left over from a supernova that occurred 3,700 years ago. The cloud, called Puppis A, is around 7,000 light-years away, and the shock wave is about 10 light-years across. UPI/NASA