NASA's Hubble Telescope

The Hubble Deep Field photographs are historical achievements in the search for understanding our position in the Universe. These photographs allowed scientists a much better observational understanding of fundamental Laws such as Gravity, Physics and many more of the Sciences. By giving us a glimpse into the depths on space we can challenge ideas, theories and facts. This series of Hubble photographs allow researchers to see the complexities of galaxies and predict how they formed and even what they could be made of.

The Ultra Deep Fields show the furthest away galaxies that can be observed in visible light. Because the Universe expands, light waves from very distant objects are stretched during its long journey to us. The further away objects are from us, the more their light is stretched. As longer wavelengths appear redder than shorter wavelengths, this phenomenon is known as “redshift”, and it is somewhat similar to the Doppler Effect heard when an ambulance siren drops in pitch as the vehicle speeds away. For very distant objects, their light is shifted so far that they drop out of the visible spectrum altogether, and can only be seen in infrared light. This means that the Hubble Ultra Deep Field cannot be improved on by building a more sensitive optical telescope — Hubble has reached the limit of what is possible in visible light.

The HUDF is the deepest visible-light image of the universe ever observed by a telescope. The image shows about 10,000 galaxies, and is like a geologic core sample of the universe, cutting across billions of light-years of space. Hubble took 800 exposures in 400 orbits to build this image. The HUDF is found in the constellation Fornax, located in the Southern Hemisphere. This region of the sky is so empty that only a handful of the stars within our Milky Way Galaxy can be seen in the image.