The “grand design” spiral galaxy visible in Hubble’s photo of M101 is known as the Pinwheel Galaxy. Its official designation is Messier 101 (M101), and it is located in the constellation Ursa Major. What distinguishes M101 as a “grand design” spiral is its well-defined structure with prominent, graceful spiral arms. Grand design spirals typically have a clear two-arm pattern as opposed to other galaxies that might have a more flocculent, or fluffy, appearance. Located about 21 million light-years away from Earth, M101 reveals exquisite details of star formation, nebulae, and the structure of spiral arms, thanks to the clarity of the Hubble Space Telescope imagery.