Hubble Ultra Deep Field
The Hubble Ultra-Deep Field is an image taken by the Hubble Space Telescope of a small patch of sky containing nearly 10,000 galaxies. Taken in 2004, it is furthest image ever made in visible light, in fact infrared light must be used to see further. Similar images were also made in the ultraviolet and infrared bands. The image was created using 800 different exposures producing a combined exposure time of 11.3 days.
The photograph is of a small area of sky in the Fornax constellation, below the constellation of Orion. This area was chosen as it does not lie in the plane of the Milky Way, reducing the number of Milky Way's own stars in the image. The image is 2.3 arcminutes across, about a tenth the width of a full moon.