Hubble Deep Field Galaxies

1995 HDF-N from Ursa Major
2012 combination image from Fornax
3.544hr -27.791°

    The sensitivity of Hubble can be described as sufficient, if there were no atmosphere in the way, to both see and resolve two lightning bugs on the headlights of a car 3000 miles away on the opposite coast of the US.

    The first 1995 Deep Field photograph was taken using a 100 hour exposure with Hubble pointing at a blank region of Ursa Major. It was a risky thing to do, because Hubble time is valuable, and no one knew what was going to happen. Later shots in 2012 and 2014 have been at different regions of the sky with fuller ultraviolet to infrared sensitivity and called Ultra Deep Field.

    The astonishing result has been followed by many other images as Hubble repair has improved spectral sensitivity in 1995 (HDF-N) in Ursa Major, 1996 HDF-S, 2004 HUDF in Fornax and 2009 HUDF

    The photograph released in 2012 called Hubble eXtreme Deep Field is a composite image from many sensors looking at the same patch of sky over 10 years. Total combined exposure time is 22 days.