The Hubble Ultra Deep Field (HUDF) peers deeper into the universe than any previous visible-light image. Multiple observations of the same small patch of sky were combined for an equivalent exposure time of more than 11 days. Revealed within the image are thousands of galaxies located many billions of light-years away. Many of these galaxies are too small and too faint to be otherwise seen. Most importantly, because the light from distant galaxies requires billions of years to cross the intervening space, astronomers get to see them as they were billions of years ago. Much of the history of galaxy development can be found within the HUDF image.
This scientific visualization flies through a 3D model of the HUDF galaxies. Each of the more than 5,000 galaxies in the model was cut out of the HUDF image and placed at its appropriate distance (as calculated from redshift measurements). The virtual camera flies through this long, thin galaxy dataset, showing how galaxy sizes, shapes, and colors change as one looks both out in space and back in time. Note that, in order to traverse the cosmos in a reasonable amount of time, the distance scale in the model was compressed by a factor of a few hundred.