
The Pinwheel Galaxy (M101) is a stunning face-on spiral in Ursa Major whose disk spans about 170,000 light-years — nearly twice the width of our Milky Way — making it one of the largest spiral galaxies known. It is famous for the iconic, ultra-detailed NASA/ESA Hubble portrait that reveals its sweeping arms studded with brilliant blue star clusters and glowing pink star-forming nebulae.