Ultraviolet

Badges that measure doses of sunlight have been developed by a San Diego company for people worried about the thinning ozone layer and the effects of ultraviolet rays on the skin.The badges are similar in concept to the ones worn by X-ray technicians to measure cumulative doses of radiation. Called Sun Alert, each badge consists of a plastic circle about an inch in diameter with an adhesive backing that adheres to clothing or skin.Within an inner circle is a depiction of the sun wearing sunglasses.

Chilean scientists say they are receiving reports of increases in skin allergies and sunburn among schoolchildren and of vision loss among sheep in the southernmost areas of the country. They attribute the phenomena to increased solar radiation caused by depletion of the ozone layer over the Antarctic.Chilean researchers said they believed that the sheep were getting cataracts from exposure to ultraviolet rays that would normally be blocked by atmospheric ozone. They also expressed their concern about the long-term impact on people and animals, although no increase in skin cancer has been reported in southern Chile.

Q: My doctor has told me to wear sunglasses to protect my eyes from exposure to ultraviolet light. What sunglasses should I buy?A: Ultraviolet-B (UV-B) light is potentially harmful to the eyes. The American National Standards Institute has established the following three types of labels for sunglasses based on their ability to block UV-B light: special purpose, general purpose and cosmetic. The American Academy of Ophthalmology recommends you purchase general-purpose sunglasses, which are made for daily wear and may be labeled "Blocks All UV-B" or "Blocks 95 percent UV-B," unless you plan to engage in high-exposure activities such as skiing.

The roller-coaster saga of the Astro-1 space shuttle mission took another stomach-churning plunge early yesterday with the shutdown of an essential computer terminal the astronauts had used with great success to point the instruments at celestial targets Wednesday night.But the National Aeronautics and Space Administration, after a frenzied day of trouble-shooting, was successful yesterday evening in restoring the $150 million observatory to limited operation through a complex combination of ground controls from Marshall Space Flight Center and manual fine-pointing by the astronauts.

The Astro observatory of ultraviolet telescopes has been spared the budget ax and will fly again aboard a space shuttle in 1993, reversing an earlier NASA decision to end the project after its successful first mission last December.Sen. Barbara A. Mikulski, D.-Md., and NASA's chief scientist, Lennard Fisk, made the announcement yesterday at the Johns Hopkins University, home of one of the Astro instruments and astrophysicist Samuel T. Durrance, a payload specialist on the nine-day December mission.

Sunglasses fascinate society, often for all the wrong reasons. We long to purchase the latest trends and styles. We wear sunglasses indoors and at night. We perch them on top of our heads and hang them around our necks as much as we use them for the reason they were invented.The American Optometric Association (AOA) calculates that nearly $2 billion is spent each year on an estimated 105 million pairs of sunglasses.But the perceived mystique and glamour of sunglasses, and the "coolness" associated with wearing them, should never be overshadowed by a more important issue: Wearing quality sunglasses can protect your eyes against exposure to the harmful ultraviolet (UV)

If you want to learn more about some of the hottest, most violent objects in the universe, you'll have to launch yourself beyond the curtain of Earth's atmosphere and pack telescopes tuned to light frequencies no one has ever looked at before.That's just what two Maryland astronauts -- Dr. Samuel T. Durrance of Lutherville and Dr. Ronald A. Parise of Silver Spring -- plan to do Thursday aboard the shuttle Endeavour, on their second mission with the Astro ultraviolet observatory.Dr. Durrance, 51, is the oldest crew member and an astrogeophysicist and research scientist at the Johns Hopkins University.

WASHINGTON -- Astronomers using the Hubble Space Telescope spotted a brief flash of ultraviolet light just before a massive explosion on a puny star, a discovery that may help explain the cause of solar flares.When a flare occurs on the sun, it can block radio communications, disrupt power supplies and threaten the health of astronauts. Some scientists think that the long-term cycles of solar flares may alter Earth's climate.Bruce E. Woodgate, an astronomer with the Goddard Space Flight Center, said yesterday that one of the Hubble's light-analyzing spectrographs was pointed at a star called AU Microscopium last Sept.

A series of environmental dominoes beginning with global climate change may explain one of the decade's most perplexing biological mysteries - the sharp decline in amphibians - according to a new study of toads in Oregon. A team of researchers studying western toads in the Cascade Range has tied together a series of seemingly unrelated events, warm weather patterns over the South Pacific, decreased rainfall in the Pacific Northwest, ultraviolet radiation and a fungus-like pathogen. Simply put: The research team found that unusually dry winters caused by El Nino meant ponds in which toad embryos mature contained less water, making them more vulnerable to both ultraviolet radiation and a destructive fungus.

Amid the clatter and dust of huge machines connected by conveyor belts and catwalks, the newspapers, plastic bags, cardboard, cans and bottles come flying at workers who frantically pluck unwanted items from the recycling stream. Screens and spinning, star-shaped black plastic devices separate newspaper from cans and bottles. The fast-rotating stars push the paper higher up an inclined screen; the heavier, smaller cans and bottles tumble down to a different level.