Hubble's deep southern stare.

Staring down a corridor 12 billion light-years long the Hubble Space Telescope has revealed thousands of previously unseen galaxies that will help scientists decipher the early universe. The colorful spiral and elliptical galaxies pictured here are only a few of those captured during the 10 days in October that the orbiter peered at a pinpoint of space in the southern constellation Tucana.

Hubble's first penetrating look--at a northern spot in the Big Dipper in 1995 (SN: 1/20/96, p. 36)--revolutionized deep-space studies. The new view offers a point of comparison, but both surveys cover such tiny areas that "it would take a million years to fill in the whole sky" in this way, says Robert E. Williams of the Space Telescope Science Institute in Baltimore.

For Hubble Deep Field-South, Williams' team of 50 scientists used a trio of cameras, two installed by astronauts since the northern field was imaged, to extend the view into both ultraviolet and near-infrared light. The field includes a quasar, an intense beacon of light about 10 billion light-years away. The image of the quasar (inset, upper left) depicts the deepest view of the universe ever taken in visible light.

Astronomers at the Anglo-Australian Observatory in Epping, Australia, helped the Hubble team choose the quasar for observation. With their ground-based telescope, the Australian team has been using the quasar as an "intergalactic searchlight" to detect otherwise invisible clouds of gas lying between Earth and the quasar, says observatory director Brian Boyle. Hubble's long look detected clouds and structural details of related galaxies that the Australian telescope can't see. These gas clouds take a distinctive bite out of the quasar's light signature, indicating their composition and distance from Earth. Matching galaxies to the clouds from which they arose tells researchers about galaxy evolution.

Both groups released their data this week. Williams expects combined analyses to be presented in January.