Andromeda Galaxy - M31 The Andromeda Galaxy is the nearest major galaxy to our own Milky Way Galaxy, and is visible to the naked eye as a light colored smudge in the constellation Andromeda. Our Galaxy is thought to look much the same. The distinct stars that surround Andromeda's image are actually stars in our Galaxy that are well in front of M31 in the background 2 million light years away. Andromeda is frequently referred to as M31 since it is the 31st object on Messier's list of diffuse sky objects. The smaller elliptical galaxy to the lower right is M110. The bright elliptical galaxy to the left of center is M32. Galaxies M31, M32, and M110 are all members of the so called "local group" of about 30 galaxies that populate this neighborhood in our Universe. To give you some idea of the scale, if our galaxy were the size of a dime and located here near San Diego, The Andromeda Galaxy (M31) would also be about the size of a dime and located near Boston. In between there would be virtually no visible matter, although it's worth noting that 95% of the mass of our universe is "missing," invisible, and so far unaccounted for. So the space between here and Boston may well contain substantial hidden "matter." Another way to visualize the immense distances (and empty space) involved, consider that our galaxy alone is comprised of something over two hundred billion stars ranging in size from smaller than the Earth to larger than Saturn's orbit--the Earth would actually be swallowed up inside the giant. But consider that a few dozen baseballs scattered across North America would crowd each other by comparison to the space between average stars in average galaxies. Imagine sixty round objects including a dozen the size of baseballs, tennis balls, golf balls, and marbles (the rest are all much smaller ranging from pea-size to bare specs). Spread them equally in a volume about the size of the Earth. You have a reasonable scale model of the nearby (1000 light years) of space