Stars from an alien galaxy are raining down on our own Milky Way and passing just a few hundred light-years from Earth. That's the conclusion of astronomers who have mapped the extent of the Sagittarius dwarf galaxy, one of two dwarf galaxies that the Milky Way's gravity is ripping apart (SN: 11/15/03, p. 307: Available to subscribers at Chow Down! Milky Way gobbles its closest known neighbor).
When a dwarf galaxy passes close to the Milky Way, its leading edge gets pulled more strongly by our galaxy's gravity than its trailing edge does. The unequal tugs stretch the dwarf, pulling stars out in spaghetti-like streams.