Hubble's Extreme Deep Field- Called the eXtreme Deep Field, or XDF, the photo was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a patch of sky at the center of the original Hubble Ultra Deep Field.
The Hubble Space Telescope accumulated approximately 555 hours of exposure time to capture this Hubble eXtreme Deep Field image. The area shown represents a seemingly empty patch of sky about the width of a toothpick when held at arm's length. The picture contains only two foreground stars (indicated by surrounding spikes). Every other object is a galaxy. The most distant galaxies' light is reddened by the expansion of the universe. We're seeing light that left them 13.2 billion years ago.
Cosmology - The Hubble eXtreme Deep Field (XDF) was completed in September 2012 and shows the farthest galaxies ever photographed by humans. Except for the few stars in the foreground (which are bright and easily recognizable because only they have diffraction spikes), every speck of light in the photo is an individual galaxy, some of them as old as 13.2 billion years; the observable universe is estimated to contain more than 200 billion galaxies