These three images represent select portions of the sky as seen in the Hubble Deep Field observation – the "deepest-ever" view of the universe, made with NASA's Hubble Space Telescope.
The images, extracted from the Hubble Deep Field (HDF), were assembled from many separate exposures (342 frames total were taken, 276 have been fully processed to date and used for this picture) with the Wide Field and Planetary Camera 2 (WFPC2), for ten consecutive days between December 18 to 28, 1995.
Besides the classical spiral- and elliptical-shaped galaxies, there is a bewildering variety of other galaxy shapes and colors. The never before seen dimmest galaxies are nearly 30th magnitude.
Representing a narrow "keyhole" view stretching all the way to the visible horizon of the universe, the HDF image covers a speck of sky a tiny fraction the diameter of the full Moon. This is so narrow, just a few foreground stars in our Milky Way Galaxy are visible and are vastly outnumbered by the menagerie of far more distant galaxies.
Though the field is a very small sample of sky, it is considered representative of the typical distribution of galaxies in space because the universe, statistically, looks the same in all directions. The HDF will provide important clues to understanding the evolution of the universe. Some of the galaxies may have formed less that one billion years after the Big Bang.
This "true-color" view was assembled from separate images were taken in blue, red, and infrared light. By combining these separate images into a single color picture, astronomers will be able to infer – at least statistically – the distance, age, and composition of galaxies. Bluer objects contain young stars and/or are relatively close, while redder objects contain older stellar populations and/or are farther away.
This material was presented to the 187th meeting of the American Astronomical Society in San Antonio, Texas on January 15, 1996.