M101

I wonder if Charles Messier ever even imagined that someday his catalog of beautiful objects in the sky could be seen in such detail?

From APOD (of course!):

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 galaxy. 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 of M101 is touted as the largest, most detailed spiral galaxy view ever released from Hubble. The sharp image shows stunning features along 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.

If you’re not familiar with Charles Messier and his famous catalog of celestial objects, you might be interested to know more about him. Wikipedia has short articles on both Messier and his catalog. The photo at right is a visual catalog of all 110 “Messier Objects”.

As usual, click on the small photo for a larger view…