Hubble obtains deepest space view

By Dr David Whitehouse
BBC News Online science editor

A sneak preview of the Hubble Ultra Deep Field

The Hubble Space Telescope has imaged the deepest view ever of the cosmos, detecting the oldest and most distant galaxies ever seen by astronomers.

The Hubble Ultra Deep Field is the result of an unprecedented look over four months at just one patch of sky.

According to scientists, the picture reaches back to the Universe's "Dark Ages", before the first stars formed.

The image, which will be released in February, will be a major advance in our understanding of the cosmos.

Beautiful, rich, intriguing

Hubble has been peering at the same point in the heavens since September. Its detailed scrutiny of the region ends on 16 January.

Steven Beckwith, director of the Space Telescope Science Institute, told BBC News Online: "We have seen things that are fainter than anyone has ever seen before."

Steven Beckwith: "...fainter than anyone has ever seen before"

The purpose of the prolonged observation was to create a deeper "borehole" through the Universe than was obtained by the now famous "Hubble Deep Field (HDF)" in 1996.

"I have put an enormous amount of director's discretionary time into this project - 400 orbits - twice as much time as the original Hubble Deep Field, and you have to remember that Hubble's detectors are now tens of times more sensitive," Dr Beckwith said.

These boreholes blaze a trail through the Universe which other telescopes follow, picking over the details of the objects Hubble has signposted.

To get the ultra deep field (HUDF), Hubble has been using what many consider is its most impressive detector - the Advanced Camera for Surveys.

And the resulting image is, according to Dr Beckwith: "Just beautiful - rich, with many different, intriguing things."

Scientific highlight

But choosing the site of the celestial borehole was not a straightforward task.

"We wanted a field free of other things so that we could get a clear sight to the edge of the Universe," said Dr Beckwith.

In addition, the field had to be observable from both northern and southern hemispheres and easy to view with Alma, the array of microwave telescopes being constructed in South America.

Deeper than the original Hubble Deep Field

"We picked a field free of bright stars, X-ray objects and bright radio sources. There were only a few places that were suitable."

The HUDF image is not yet complete and what has been obtained is mostly under wraps, although BBC News Online has obtained a small thumbnail.

"It is gorgeous, much prettier than the HDF; the camera is far better. There are a few clusters of galaxies in different parts of the field that grab the eye.

"Then there are red stringy objects nestling at the edge of the Universe."

Hubble astronomers have already released some information from the UDF. They have circulated a list of coordinates of the faintest objects seen in it in the hope that other telescopes can be turned towards them as well.

But those not privileged to see the image as it is processed at the Space Telescope Science Institute in Baltimore, Maryland, US, will have to wait until February to see the image in what will certainly be one of the scientific highlights of the decade.

Asked how Hubble is performing Dr Beckwith said: "Hubble is doing beautifully. It's working better than when it was new. We have not yet reached the limit of what it can do."