Hubble Ultra Deep Field Most-Distant Galaxy Candidates - Close-up 1

This image of the Hubble Ultra Deep Field (HUDF) — a small region of sky in the direction of the southern constellation Fornax — shows some of the earliest star-forming galaxies in the Universe.

The sensitivity of Hubble's Advanced Camera for Surveys (ACS), combined with the penetrating power of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) have finally revealed these long-sought after faint galaxies. Some of these faint objects are less than one four-billionth the brightness of stars that can be seen with the naked eye and their light has taken nearly 13 billion years to reach Earth.