WISE

Credit: NASA/JPL-Caltech/UCLA

Observation • May 25th, 2011

Known by astronomers as M51, this beauty is a grand design spiral, which are galaxies with well-defined spiral arms. Its smaller companion, a dwarf galaxy called NGC 5195, is thought to have helped define and shape the arms due to its gravitational "dance" with its larger partner. M51 is also known as "The Lord Ross Galaxy," after the astronomer who was the first to study its spiral structure in the 1840s. It is located 25 million light-years away in the constellation Canes Venatici, and is 81,000 light-years across.