Messier 101, The Pinwheel Galaxy in Ursa Major.

ASTRONOMY • ASTROPHOTOGRAPHY • BIG BEAR • BIG DIPPER = BIG BEAR = PLOW, THE = PLOUGH, THE • BIG DIPPER • CELESTIAL • CENTER • COLOR IMAGE • CONSTELLATION • CORE • COSMIC DUST • COSMOLOGY • COSMOS • DEEP SPACE • GALACTIC • GALAXY • H II REGIONS • HEAVENLY • HORIZONTAL • M101 • MAJESTIC • MESSIER 101 • MOLECULAR CLOUDS • NGC 5441 • NGC 5447 • NGC 5451 • NGC 5453 • NGC 5457 • NGC 5458 • NGC 5461 • NGC 5462 • NGC 5471 • NIGHT • NO PEOPLE • NUCLEUS • OUTDOOR • OUTDOORS • OUTERSPACE • OUTSIDE • PHOTOGRAPHY • PINWHEEL GALAXY • PLOUGH, THE • PLOW, THE • RADIAL • SHINING • SPACE (COSMOS) • SPACE EXPLORATION • SPACE • SPATIAL • SPIRAL (SHAPE) • SPIRAL ARMS • SPIRAL GALAXY • SPIRAL • STAR FORMATION • STARFORMING • STARLIGHT • STARS • STELLAR • UNIVERSE • URSA MAJOR • WITHOUT PEOPLE