Andromeda galaxy (M31). North is at top. This large spiral galaxy is the nearest major galaxy to our own Milky Way, lying around 2.5 million light years from Earth, in the constellation Andromeda. It is orbited by two satellite galaxies, M32 (bright dot below M31's nucleus) and M101 (above and right of M31's nucleus). The bright star at centre left is Nu Andromedae. Photographed by the 1.22-metre Oschin Telescope at Mount Palomar, California, USA.