Hubble Finds Most Distant Galaxies Yet

U.S. scientists working with images from the Hubble Space Telescope have identified what may turn out to be some of the earliest star-forming galaxies.

Using images collected by the orbiting telescope from a tiny patch of the night sky over a period of six months, the scientists have found about 50 galaxies whose age places them about 95 percent back toward the Big Bang, the gigantic expansion that created the known universe.

The ancient galaxies emerged at about the time scientists think the universe suddenly lost its perpetual fog of cold hydrogen that had persisted since relatively soon after the Big Bang.

The exact source of this phenomenon, called re-ionization, remains unknown. But the scientists suspect the galaxies — most of which are much smaller than the Milky Way — generated enough radiation to strip the primordial hydrogen of electrons and allow light-carrying photons to travel indefinitely without interference.

In effect, re-ionization made it possible to see other stars and galaxies.