The Andromeda galaxy is the largest nearby galaxy. It’s about twice the diameter of our Milky Way and only about 2.5 million light years away. Given a dark, clear sky, it’s visible to the naked eye. This false-color image is from infrared data taken by the Spitzer Space Telescope. It was assembled from around 3,000 separate frames.
Image Credit: NASA
You might have seen this picture floating around the net last week, but I thought it was fascinating (if questionable). It is a composite showing the actual size of Andromeda in the night sky if it were brighter.
Seems a little big to me.