This impressive color composite shows spiral galaxy M81 across the electromagnetic spectrum. It combines X-ray data (blue) from the Chandra Observatory, infrared data (pink) from the Spitzer Space Telescope, and an ultraviolet image (purple) from the GALEX satellite, with a visible light (green) Hubble image.

In the left corner, wearing a red nucleus surrounded by blue spiral arms, is M81. In the right corner, sporting light stars and dark dust lanes, is M82. These two mammoth galaxies have been locked in gravitational combat for the past billion years.

In 1993, a star in the galaxy M81 exploded. Above is a picture of the hot material ejected by this supernova explosion. The picture was taken in X-rays with the Advanced Satellite for Cosmology and Astrophysics (ASCA).