M101, also known as the pinwheel galaxy, is a spiral galaxy in Ursa Major, and is the largest member of a galaxy cluster called the M101 group. It was one of the first galaxies found to have a spiral structure.
M101, also known as the pinwheel galaxy, is a spiral galaxy in Ursa Major, and is the largest member of a galaxy cluster called the M101 group. It was one of the first galaxies found to have a spiral structure.