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Credit & Copyright: NASA,  
ESA,  
CFHT,  
NOAO;  
Acknowledgement - K.Kuntz (GSFC), F.Bresolin (U.Hawaii), J.Trauger (JPL), J.Mould (NOAO), Y.-H.Chu (U. Illinois)
Explanation:
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.  
  
Acknowledgement - K.Kuntz (GSFC), F.Bresolin (U.Hawaii), J.Trauger (JPL), J.Mould (NOAO), Y.-H.Chu (U. Illinois)
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: M 101 - spiral galaxy
Publications with words: M 101 - spiral galaxy
See also:
- APOD: 2025 September 4 Á NGC 4565: Galaxy on Edge
 - APOD: 2025 August 22 Á A Tale of Two Nebulae
 - APOD: 2025 August 19 Á Giant Galaxies in Pavo
 - APOD: 2025 August 18 Á NGC 1309: A Useful Spiral Galaxy
 - APOD: 2025 July 4 Á NGC 6946 and NGC 6939
 - APOD: 2025 June 30 Á NGC 4651: The Umbrella Galaxy
 - APOD: 2025 June 19 Á NGC 3521: Galaxy in a Bubble
 

