SCIENCE / MEDICINE : Telescope Planned for Clear-Skied Antarctica

Every cloud has a silver lining.

Astronomers from Australia and the United States said last week that they plan to build a large telescope atop an icy plateau near the South Pole, in part because the ozone hole over that continent would allow better viewing of the universe.

“The advantages are great,” said astronomer John Storey of the University of New South Wales. “The atmosphere (there) is very stable and very thin, and star images are very sharp. There are long periods of darkness during which astronomers could study stars.”

And, for at least three months of the year, from October through December, the stratosphere over Antarctica contains as little as half the normal amount of ultraviolet light-absorbing ozone--a fact that would facilitate observing the universe in wavelengths that are normally obscured by the Earth’s atmosphere.

The ozone hole is caused by man-made chemicals called chlorofluorocarbons, which are used as refrigerants and solvents. When sunlight returns to the Antarctic after the long polar winter, it triggers a massive destruction of ozone by the chemicals.