The Whirlpool Galaxy - M51

The Whirlpool Galaxy, also known as M51, is located 31 million light-years from Earth in the constellation Canes Venatici. Compared to other galaxies in the night sky, M51 is pretty bright with an apparent magnitude of 8.4. Under the darkest of skies, humans can see stars, galaxies and other deep space objects that shine at about magnitude 6. With magnitudes, the smaller the number - the brighter the object. For comparison, the magnitude of the north star (Polaris) is about 2 and Venus is about -4. The Whirlpool galaxy was discovered by none other than Charles Messier in 1773.

The small, yellowish galaxy at the outermost tip of one of the arms of M51 is NGC 5195. It is actually passing behind M51 from our perspective here on Earth. This small compact galaxy has been gliding past the M51 for hundreds of millions of years.