NASA Astronomy Picture of the Day 2 June 2023: Pinwheel Galaxy Messier 101

French astronomer Charles Messier has been one of the most influential figures in the history of astronomy with major contributions in finding and studying comets, nebulae, and more. Although Messier was an avid comet hunter, some of his most amazing discoveries include several nebulae such as the Crab Nebula, Dumbbell Nebula, the Pleiades star cluster, and more. Messier studied and catalogued these objects in Catalogue des Nebuleuses et des Amas d'Etoiles and the catalogue is today known as the Messier Objects.

Today’s NASA Astronomy Picture of the Day is a snapshot of Messier 101, also known as the Pinwheel Galaxy which is located about 25 million light-years away towards the Northern constellation of Ursa Major. Messier 101 is one of the last objects catalogued by Charles Messier and it is a massive pinwheel galaxy that spans about 170,000 light-years across. According to NASA, Messier 101 is also one of the first spiral nebulae to be observed by Lord Rosse's large 19th-century telescope, the Leviathan of Parsontown.

Tech used to capture the picture

This awesome picture was captured by the Hubble Space Telescope, which is run by NASA in collaboration with ESA. Hubble has advanced optical instruments such as the Advanced Camera for Surveys and Wide Field Camera 3. The Advanced Camera for Surveys (ACS) was primarily designed to survey large areas of the sky at visible and red wavelengths with 10 times greater efficiency than the earlier premier Hubble camera.

NASA’s description of the picture

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. Assembled from 51 exposures recorded by the Hubble Space Telescope in the 20th and 21st centuries, with additional data from ground based telescopes, this mosaic spans about 40,000 light-years across the central region of M101 in one of the highest definition spiral galaxy portraits ever released from Hubble.

The sharp image shows stunning features of the galaxy's face-on disk of stars and dust along with background galaxies, some visible right through M101 itself. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away.