M51. /National Aeronautics and Space Administration (NASA)

This is M51 (NGC 5194), also known as the Whirlpool Galaxy. The small reddish-brown galaxy next to it is NGC 5195. M51 is located about 3.5° from Eta, at the end of the handle of the Big Dipper, but it belongs to the constellation Canes Venatici. The two galaxies are colliding, and M51's winding spiral arms have given rise to its nickname, the Whirlpool Galaxy. The two galaxies (NGC 5194, NGC 5195) are also referred to as the 'Father and Son Galaxy' due to their resemblance to a father and son. NGC 5195 is in a torn state due to the strong gravitational pull of M51. In contrast, M51 is undergoing massive structural alterations that are leading to star births due to the gravitational influence of NGC 5195.