Giant galaxies weren't assembled in a day. Neither was this Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (M101). It is the largest and most detailed photo of a spiral galaxy that has ever been released from Hubble. The galaxy's portrait is actually composed of 51 individual exposures taken with Hubble's Advanced Camera for Surveys and the Wide Field and Planetary Camera 2 in March 1994, September 1994, June 1999, November 2002, and January 2003. The newly composed image also includes elements from images from ground-based photos.