Hubble images show deepest view of the universe, stars forming out

BALTIMORE (AP) — The deepest-ever view of the universe, a photo by the Hubble Space Telescope that looks back to the edge of the big bang, shows a chaotic scramble of odd galaxies smashing into each other and re-forming in bizarre shapes.

The snapshot of the universe, called the Ultra Deep Field, captured light that had streaked through space for more than 13 billion years, starting its journey when the universe was only 5 percent of its 13.7-billion-year age. The view has about 10,000 galaxies, some mixed in chaos that one astronomer said “looked like a train wreck.”

Capturing such faint and distant light, officials at the Space Telescope Science Institute said Tuesday, was like photographing a firefly hovering above the moon.

“For the first time we’re looking back at stars that are forming out of the depths of the big bang,” said Steven V. W. Beckwith, director of the institute. “We’re seeing the youngest stars within a stone’s throw of the beginning of the universe.”

Hubble’s images were collected by focusing its instruments at a single point in the southern sky for 1 million seconds, an exposure that took more than 400 orbits of the space telescope.

The portion in the sky photographed by two Hubble instruments is very small. Astronomers compared the field of view it to looking at the sky through a 2.4-meter-long (8-foot) soda straw. They said capturing the images is akin to reading the mint date on a 25-cent coin from a mile away.

What the view lacks in width, however, it makes up for in depth. Beckwith said that never before had a telescope captured such detail from such a distance.

“These images will be in astronomy textbooks for years,” he said.

Many of the photographed galaxies lack the stately grace and order of spirals, such as the Milky Way, or of the huge elliptical galaxies seen in the nearby universe. Some of the galaxies in the Ultra Deep Field appear to be colliding, with gravitational forces mashing them into unusual shapes. Some resemble toothpicks and others are like a string of faint lights. There also are faint points of vivid red, which may be the most distant and ancient of the galaxies.

Astronomers believe that during the few hundred million years of star formation, the universe was smaller, the objects closer together and galaxy formation more chaotic.

In what Beckwith described as a “land rush,” astronomers worldwide now will begin an intensive study of the deep field view, searching for clues to fundamental questions about the formation and evolution of stars and galaxies.

“Getting us the deepest picture of the universe ever is giving us new land to explore,” said Massimo Stiavelli, a Space Telescope Science Institute astronomer.

Release of the Ultra Deep Field may be among the Hubble’s last major contribution to astronomy. Maintaining the orbiting telescope requires periodic repair visits by space shuttle astronauts. NASA has announced that, in the aftermath of the Columbia accident in 2003, it is canceling future plans to service the Hubble.

Beckwith said the Hubble batteries or gyroscopes eventually will fail and disable the observatory. He said it may be down to two gyros by the end of 2005, and if another fails after that, “We’ll be out of business.”

“We don’t know exactly when that will happen,” he said. “It could happen this year, or it could be another five years.”

Current theory holds that the universe started with an immense explosion, called the big bang, about 13.7 billion years ago. During the next 300 million years or so the universe cooled and was dark, lacking stars.

First stars and then galaxies begin to form, and it’s light from these very early objects that has been captured by Hubble, astronomers believe.

Just how far away is the most distant object in the photos will require analysis and study of the data, a process that could take years.

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On the Net:

Hubble: http://hubblesite.org/news/2004/07

Space Telescope Science Institute: http://www.spacetelescope.org