M101 (NGC 5457) is often referred to as The Pinwheel Galaxy and ranks as a favorite among astrophotographers alongside The Triangulum Galaxy. M101 is a face-on spiral galaxy as opposed to an edge-on galaxy (see the Needle Galaxy). M101 is nearly twice the diameter of our Milky Way galaxy and is estimated to contain over a trillion stars. At a distance of 25 million light years from the earth, the light that left M101 (which has traveled through space and produced this image) left the Pinwheel Galaxy at the beginning of Earth’s Miocene period when the mastodon roamed the earth.

Approximately 100 billion of the Pinwheel Galaxy stars are similar to our sun in terms of temperature and stage of development. Looking closely at the arms of the spiral, you can see numerous regions of nebulae and clumps of extreme heat and dust, perfect conditions for the formation of new stars. The spiral arms reveal strings of blue, white stars, or relatively young suns, stretching into the surrounding darkness.