Space telescope challenges theories of universe

When it was launched in 1990, astronomers predicted that the powerful new Hubble Space Telescope would upset a lot of theoretical apple carts on its way to new discoveries.

Three new reports from Hubble astronomers, presented Monday at the 179th meeting of the American Astronomical Society in Atlanta are challenging theories relating to "gravitational lenses," intergalactic hydrogen clouds and the chemistry of the early universe.

Scientists from the Space Telescope Science Institute and from the University of Texas in Austin have been surprised by evidence of boron in a Hubble spectrograph of light from a star only 100 light years away in the Libra constellation.

Boron and another light element, beryllium, might have been formed by cosmic rays during the birth of the Milky Way Galaxy, scientists say, but not in the exact proportions found by Hubble.

That opens the possibility that this boron may have been created billions of years earlier, just after the Big Bang.

That, scientists told the Baltimore Sun, would lend support to new theories that the universe immediately after the Big Bang was not as uniformly hot and dense as once thought.

The competing theories will be tested later this year as astronomers use Hubble to look for boron in an even older star.

If the boron was created by cosmic rays in the young Milky Way, there should be less of it in an older star. If all the boron was created in the Big Bang billions of years before, the amounts found in the stars should be the same.

In another report, a "snapshot" survey of 300 distant quasars found only one whose light appeared to have been bent and split into multiple images by the intense gravity of intervening matter.

Those split images of bright quasars are a valuable tool for astronomers working to find out how much invisible "dark matter" exists in the universe.

Ground telescopes had found about a dozen examples of such "gravitational lensing," and some scientists had predicted that many more would be detected by sharper-eyed, space-based telescopes.

But Hubble's findings may indicate new limits on dark matter, said John Bachall of the Institute for Advanced Study in Princeton, N.J.