The Andromeda Galaxy (M31) as seen by the 200-inch optical telescope at the Palomar Observatory. Like the Milky Way, Andromeda is a spiral galaxy orbited by Two companion galaxies, seen as bright spots above and below the Andromeda. Andromeda is approximately 20,000 light years across, and about 2 million light years away. (One light year is 9.5 trillion miles.) It is the nearest spiral galaxy similar to the Milky Way.