NASA Astronomy Picture of the Day Collection

Messier 101

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's [ http://antwrp.gsfc.…] famous catalog, but definitely not one [ http://www.seds.org…] 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 [ http://www.seds.org…] observed by Lord Rosse's large 19th century telescope, the Leviathan [ http://www.birrcast…] 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 [ http://hubblesite.o…releases/2006/10/ ] is touted as the largest, most detailed spiral galaxy [ http://heritage.sts…] view ever released from Hubble. The sharp image [ http://hubblesite.o…releases/2006/10/fas tfacts/ ] shows stunning features [ http://hubblesite.o…releases/2006/10/ima ge/a zoom ] 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 [ http://www.seds.org…] lies within the boundaries of the northern constellation Ursa Major [ http://en.wikipedia…], about 25 million light-years away.

NASA [ http://www.nasa.gov…], ESA [ http://www.spacetel…], CFHT [ http://www.cfht.haw…], NOAO [ http://www.noao.edu/]; Acknowledgement - K.Kuntz (GSFC [ http://universe.gsf…]), F.Bresolin (U.Hawaii [ http://www.ifa.hawa…]), J.Trauger (JPL [ http://www.jpl.nasa…]), J.Mould (NOAO [ http://www.noao.edu/]), Y.-H.Chu (U. Illinois [ http://www.astro.ui…])

19th century

Milky Way Galaxy

Hawaii

M101

Pinwheel Galaxy

Illinois

Goddard Space Flight Center (GSFC)

Jet Propulsion Laboratory (JPL)

Ursa Major

Messier

Hubble Space Telescope (HST)

http://antwrp.gsfc.…

SPD-APOD-ap060302