The central area of M82 shows extensive disruption. Multiple gravitational tidal encounters with neighboring galaxy M81, most recently about 300 million years ago, are considered to be the cause of the disruption. Extensive star formation "starburst" activity is evident from several brilliant clumps which are also high intensity radio, infrared and X-ray sources. The rate of new star birth in M82 is 10 times higher than normal.
The high star birth rate is accompanied by an above normal type II supernova death rate (one every 10 years). The high supernova frequency is sited as cause for a galactic "superwind" visible as faint jet-like filaments above and below the galaxy's poles. M82 also harbors a supermassive black hole at its core estimated to contain 30 million solar masses.