Word: ultraviolet
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...under the combined sponsorship of NASA, the National Oceanic and Atmospheric Administration, the National Science Foundation and the Chemical Manufacturers Association. The purpose: to find out why the layer of ozone gas in the upper atmosphere, which protects the earth's surface from lethal solar ultraviolet radiation, was badly depleted over Antarctica. The scale of the mission reflected an intensifying push to understand the detailed dynamics of potentially disastrous changes in the climate. The danger of ozone depletion is only part of the problem; scientists are also concerned about the "greenhouse effect," a long-term warming of the planet caused...
Their interest is hardly academic. The ozone-enriched air, which stretches from six to 30 miles up, protects life on earth from dangerous solar ultraviolet radiation (UV). Although ozone, whose molecules are made of three oxygen atoms, absorbs UV radiation, even the amount that now penetrates the ozone layer can cause skin cancers and has been linked to cataracts. With less ozone, these disorders will increase; with no ozone at all, the UV could be deadly. Scientists have long suspected that decomposing CFCs in the stratosphere release chlorine, which acts as a catalyst, breaking ozone molecules apart...
Fifteen years ago, scientists began noticing that the earth's protective ozone layer was being depleted by a group of chemicals known as chlorofluorocarbons. They warned that deterioration of the ozone, which blocks the sun's harmful ultraviolet rays, could lead to an increase in skin cancer and disastrous climatic changes, including an overall warming of the earth's atmosphere...
...first bright supernova since Harvard was founded," said Professor Of Astronomy Robert P. Kirshner '70, who studying ultraviolet (UV) light emitted form the bright supernova. The most recent supernova observable from Earth with the naked...
These are the theoretical scenarios. And at first 1987A seemed to be following the rules: it jumped from near invisibility to respectable brightness literally overnight, and while its wave-front speed was high, its spectrum revealed the unmistakable hydrogen-bearing signature of a Type II. But when the International Ultraviolet Explorer satellite reported a rapid drop in ultraviolet light, scientists began to wonder. Says Robert Kirshner, of the Harvard-Smithsonian Center for Astrophysics: "The spectrum we're seeing in the ultraviolet resembles the spectrum of a Type I. That's a puzzle." Admits Texas' Wheeler: "There are some funny features...