What is the closest galaxy to the Milky Way? The new answer to this old question is the Canis Major dwarf galaxy . For many years astronomers thought the Large Magellan Cloud (LMC) was closest, but its title was supplanted in 1994 by the Sagittarius dwarf galaxy . Recent measurements indicate that the Canis Major dwarf is only 42 ,000 light years from the Galactic center , about three quarters of the distance to the Sagittarius dwarf and a quarter of the distance to the LMC. The discovery was made in data from the 2MASS -sky survey, where infrared light allows a better view through our optically opaque Galactic plane . The labeled illustration above shows the location of the newly discovered Canis Major dwarf and its associated tidal stream of material in relation to our Milky Way Galaxy . The Canis Major dwarf and other satellite galaxies are slowly being gravitationally ripped apart as they travel around and through our Galaxy.
Note added in 2010: Canis Major's galaxy designation is now disputed .