Buoyed by the Hubble Deep Field, astronomers in 2004 began a new project, called the Ultra Deep Field, which made use of the new capabilities of the Advanced Camera for Surveys that was installed during a 2002 shuttle servicing mission. This time, Hubble was pointed at a small slice of the constellation Fornax (the Furnace). It revealed the most distant galaxies that can be seen in visible light.
Hubble made additional observations of its original Deep Field and the Ultra Deep Field targets with its near-infrared camera, which turned up even more distant galaxies. The Ultra Deep Field then benefitted from additional infrared scans after a new instrument was installed during the final servicing mission in 2009. Scientists then combined 2,000 exposures, ranging from the ultraviolet to the infrared, that were taken of the same region between 2002 and 2012 into the Hubble Extreme Deep Field, released in September 2012.