A new study suggests the massive star that became the Cassiopeia A supernova remnant may have turned inside out as it exploded. Comparing a "before" artist's illustration with an "after" image from Chandra shows key elements are in different areas following the explosion. These results are based on a million seconds of Chandra observing time.
Credit: Illustration: NASA/CXC/M.Weiss; X-ray: NASA/CXC/GSFC/U.Hwang & J.Laming