Explanation: The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small, faint, fuzzy patch, but because its surface brightness is so low, casual skygazers can't appreciate the galaxy's impressive extent in planet Earth's sky.
Moon Over Andromeda
http://apod.nasa.gov/apod/ap130801.html
Thu Aug 01, 2013 12:23 pm