Using NASA’s Chandra X-ray Observatory, scientists have zeroed in on a mid-mass black hole in the galaxy M82. This black hole – located 600 light years away from the center of a galaxy – may represent the missing link between smaller stellar black holes and the supermassive variety found at the centers of galaxies. The black hole in M82 packs the mass of at least 500 suns into a region about the size of the Moon. Such a black hole would require extreme conditions for its creation, such as the collapse of a “hyperstar” or the merger of scores of black holes. Although previous X-ray data from the German-U.S. Roentgen Satellite and the Japan-U.S. ASCA Satellite suggested that a mid-mass black hole might exist in M82, the crucial breakthrough came when astronomers compared the new high resolution Chandra data with optical, radio, and infrared maps of the region. They determined that most of the X-rays were coming from a single bright source.