Galaxies Seen Near 'Edge of the Universe'

July 10, 2007 — -- Long ago, in a place far, far away, the first galaxies began to form after the Big Bang that is believed to have begun the universe.

Now a team of astronomers reports it has spotted six of them and taken pictures of them from the Keck Observatory in Hawaii.

The galaxies are believed to be more than 13 billion years old -- significant because the universe is believed to be 13.7 billion years old. This is the closest anyone has seen to the dawn of time.

"We have located six star-forming galaxies seen at unprecedented distances, corresponding to a time when the universe was only 500 million years old, or less than 4 percent of its present age," said Richard Ellis of the California Institute of Technology, the lead researcher, in a statement.

The more distant an object, the longer it takes for its light to reach earthly telescopes. If indeed the newly found galaxies turn out to be as distant as their discoverers say, they must have formed not long after the formation of the universe.

Massive Volcano-Mounted Telescope

To see the galaxies, the researchers used the Keck II telescope, one of the world's largest. It is located near the top of Mauna Kea, the dormant volcano on the big island of Hawaii. It gathers light from distant objects with an array of mirrors nearly 33 feet in diameter.

Even the heavy artillery of the Keck, though, was not enough to produce the grainy image the research team released today. They pointed the telescope at a giant cluster of closer galaxies -- a cluster whose gravity is so strong that it literally bends light traveling past it. The giant cluster acted as a natural "lens," helping to magnify the light from the more distant galaxies by about 20 times.

What did they learn from the discovery? That the early universe was a busy place.

It's believed that for the first 300 million years after the Big Bang, the universe was too young and too hot for stars and galaxies to form. After that, it cooled off and entered what cosmologists call a "Dark Age" -- cold, dark, and starless.

But how long did it last? When did stars begin to form? The new discovery provides clues.

In astronomical terms, it was not long after the beginning of that Dark Age that there was light -- material coming together into galaxies, and generating enough energy to create countless stars.

The actual work was done by a Caltech graduate student named Dan Stark who spent three years making observations under Ellis' guidance.

"That we should find so many distant galaxies in our small survey area suggests they are very numerous indeed," he said in a prepared statement.

What comes next? More observations. Scientists say they are counting on new and more powerful telescopes to help them see closer to the edges of the universe.