Planetary nebula. Combined X-ray and optical image of the planetary nebula Mz 3 (also called the Ant Nebula). A planetary nebula is a bubble of hot gas and dust, many times the size of our solar system, expanding outwards from a dying, Sun-like star. The nebula consists of the ejected outer layers of the star. The optical part of this image (orange) was obtained with the Hubble Space Telescope (HST). The hotter, X-ray emitting regions (blue and white, inside the two lobes) was imaged with the Chandra X-ray Observatory (CXO). Both the HST and CXO are telescopes in Earth orbit. Mz 3 is around 3000 light years from Earth, in the constellation of Norma.