Picture of the Day

Sagittarius Galaxy impacts Milky Way's disk

This is a computer simulation showing the impact of the Sagittarius Galaxy on the disk of the Milky Way. This impact had a major influence on the development of the Milky Way's spiral arms. Also shown is the Sagittarius Stream, a long stream of stars and dark matter stripped from the Sagittarius Galaxy by the gravitational pull of the Milky Way.

Visit Website | Image credit: Erik Tollerud, Chris Purcell and James Bullock, University of California, Irvine