Hubble Ultra Deep Field
The Hubble Ultra Deep Field (HUDF) is a small region of space imaged by the Hubble Space Telescope from September 24, 2003 through January 16, 2004. The HUDF contains an estimated 10,000 galaxies. In ground-based images, the patch of sky in which the galaxies reside (just one-tenth the diameter of the full moon) is largely empty. Located in the constellation Fornax, the region is below the constellation Orion.
The million-second-long exposure reveals the first galaxies to emerge from the so-called "dark ages," the time shortly after the Big Bang when the first stars reheated the cold, dark universe. The view is actually two separate images taken by Hubble's Advanced Camera for Surveys (ACS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). In total, the image required 800 exposures taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days. It is the deepest image of the universe ever taken in visible light, looking back in time more than 13 billion years.
A question arises as to why. If the universe is supposed to have begun a finite number of years ago, when the galaxies visible in this amazing image were supposedly far younger, we do not see substantially different matter and star conglomerations and topologies than we do when looking at more "recent" visible light images of nearer galaxies.
- Hubble's Deepest View Ever of the Universe Unveils Earliest Galaxies - NASA press release
- NASA site with animations