Comparing the Local Group

Today's Astronomy Picture of the Day shows both Messier 31 and Messier 33, both members of the Local Group (of which the Milky Way is also a card-carrying member). Messier 31 is better known as the Andromeda Galaxy and can be seen (under darker skies than mine, although as few as ten years ago I could still spot it) with the naked eye (and it's a wonderful binocular or relatively low-power/wide field of view telescopic object). Messier 33 is also known as the Triangulum Galaxy, or, probably more popularly, the Pinwheel Galaxy.