Why are some supernovas much more powerful than others? Astronomers are still trying to figure that out, but one new discovery may help answer the question. On November 3, 2010, a supernova was discovered in a galaxy located about 160 million light years from Earth. When astronomers used the Chandra X-ray Observatory to look at it, they found some very interesting clues. The Chandra data showed evidence that the shock wave formed by the supernova was, in fact, breaking through a cocoon of gas. This cocoon was probably formed when the star expelled its outer layers before finally collapsing on itself and exploding as a supernova. By observing this supernova just weeks after the initial explosion, scientists were able to learn more about this supernova and potentially others as they try to better understand how some stars die.

Credit: X-ray: NASA/CXC/Royal Military College of Canada/P.Chandra et al); Optical: NASA/STScI