Princeton and University of Washington astronomers have detected a previously undiscovered dwarf galaxy on a collision course with our Milky Way Galaxy. The yet unnamed dwarf galaxy appears to have already breached the perimeter of the Milky Way and currently lies about 30,000 light years from Earth. This dwarf galaxy is apparently so close and its stars are spread over such a huge swath of the sky, that until now it has been lost in the sea of more numerous Milky Way stars. In effect, the galaxy is so close that we couldn't see it before, even though some of its individual stars have been observed with telescopes for centuries.