On Oct. 13, 1773, a French astronomer named Charles Messier discovered the “Whirlpool Galaxy,” also known as Messier 51, or M51.
Charles Messier was scanning the sky for objects that could confuse comet hunters when he catalogued the galaxy as M51. However, Messier wasn’t able to see the spiral structure, and he didn’t identify it as a galaxy.
Seventy-two years later, another astronomer named William Parsons saw the whirlpool shape, but he thought it was a spiral nebula. Eventually, Edwin Hubble found out that M51 and other features like it were actually galaxies.
Catch up on our entire “On This Day In Space” series on YouTube with this playlist.
On This Day in Space Archive!
Still not enough space? Don’t forget to check out our Space Image of the Day, and on the weekends our Best Space Photos and Top Space News Stories of the week.
Email Hanneke Weitering at firstname.lastname@example.org or follow her @hannekescience. Follow us @Spacedotcom and on Facebook.
Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: email@example.com.
Hanneke Weitering is an editor at Space.com with 10 years of experience in science journalism. She has previously written for Scholastic Classroom Magazines, MedPage Today and The Joint Institute for Computational Sciences at Oak Ridge National Laboratory. After studying physics at the University of Tennessee in her hometown of Knoxville, she earned her graduate degree in Science, Health and Environmental Reporting (SHERP) from New York University. Hanneke joined the Space.com team in 2016 as a staff writer and producer, covering topics including spaceflight and astronomy. She currently lives in Seattle, home of the Space Needle, with her cat and two snakes. In her spare time Hanneke likes to explore the Rocky Mountains, basking in nature and looking for dark skies to gaze at the cosmos.