- Messier 51 refers to the connected pair of galaxies known as Messier 51a (NGC 5194) and Messier 51b (NGC 5195). It is also known as the Whirlpool Galaxy although technically that name applies to Messier 51a rather than both.
- Messier 88 (Wikipedia)
Messier 88 (also known as M88 or NGC 4501) is a spiral galaxy about 50 to 60 million light-years away from Earth in the constellation Coma Berenices. It was discovered by Charles Messier in 1781.