Whirlpool Galaxy

The Whirlpool Galaxy (M51a or NGC 5194) is a spiral galaxy about 23 million light-years' distant that is oriented moderately close to perpendicular to the line of sight, i.e., so the spiral is fully in view. It is one of two galaxies that made up M51 in the Messier Catalog, thus its designation M51a. It is classified as a grand design spiral galaxy, i.e., showing a very clear spiral structure, and also possesses an active galactic nucleus (AGN). Its orientation makes it ideal for many observations aimed at discovering the architecture of spiral galaxies, such as the frequency, location, and density of molecular clouds.