Supernova remnant, c 2005.
© National Aeronautics & Space Administration / Science & Society
Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, saw a 'new star' in the western sky, rivalling the brilliance of the nearby planets. Astronomers using NASA's three Great Observatories are unravelling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy. This combined image - from NASA's Spitzer Space Telescope, Hubble Space Telescope, and the Chandra X-ray Observatory - unveils a bubble-shaped shroud of gas and dust that is 14 light-years wide and is expanding at 4 million miles per hour (2,000 kilometres per second). Observations from each telescope highlight distinct features of the supernova remnant, a fast-moving shell of iron-rich material from the exploded star, surrounded by an expanding shock wave that is sweeping up interstellar gas and dust.