Starburst Galaxies Revealed

Some galaxies undergo episodes of furious star formation called starbursts, producing stars at rates 10 to 100 times higher than the Milky Way. These events are often triggered by galaxy interactions or mergers that compress gas clouds and ignite waves of star birth. The nearest example is M82, about 12 million light-years away, set off by a recent gravitational encounter with its larger neighbor M81. Such intense bursts were far more common in the distant past, when galaxies collided more often.