The Pinwheel Galaxy is a face-on spiral galaxy distanced 21 million light-years away from Earth in the constellation Ursa Major. First discovered by Pierre Méchain on March 27, 1781, it was communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final entries.

Distance to Earth: 20.87 million light years

Radius: 85,000 light years

Apparent mass: ~1,000 billion M☉

Stars: 1 trillion

Apparent size (V): 28′.8 × 26′.9

Did you know: The Pinwheel Galaxy's spiral arms has more than 3,000 starbirth regions, and has the most of any similar type galaxy so far observed.