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Trying to Clean a Junkyard That's Out of This World
By WENDY KAN
Scientists are stumped over how to clear the heavens of junk left from five decades of space travel and satellite launches. Although there has been some research on using lasers to change the orbit of small debris and on employing large foam balls that would encase and slow down speeding junk (forcing pieces to drop into the atmosphere at a faster rate), these methods are not yet technically feasible. Says Gene Stansbery, an orbital debris scientist at NASA Johnson Space Center: "You can't go up and knock down or blow up a piece of debris because that just creates more particles." Scientists have focused their efforts instead on designing spacecraft that leave behind less waste, though that doesn't help clear the existing junk.
To a limited degree, the problem will sort itself out. Debris in orbits below 600 km will drift down toward Earth in a few years, and most pieces won't survive the heat of friction with the atmosphere upon reentry. Yet waste orbiting at higher altitudes isn't expected to return for decades, even centuries. Meanwhile, "every time there's a launch, more debris is added to the inventory," says Perry Nouis, a spokesman for the Colorado-based U.S. Space Command, which tracks orbital debris. Don't expect clear skies anytime soon.
Illustration for TIME by Daryll Collins
A Disaster in Waiting
Unconfirmed reports of earth-quakes in the vicinity of a Tajikistan mountain lake last week triggered panic among international disaster-relief organizations. Officials were relieved to discover that none of the tremors generated waves in the lake, but they were right to worry. Lake Sarez--formed nearly 90 years ago by an earthquake--is located in the Pamir Mountains at an elevation of 3,265 m. Earthquakes are relatively common in the area, and in a worse case scenario, a tremor could set off a dam break and wreak havoc for millions in Tajikistan, Afghanistan, Uzbekistan and Turkmenistan. Last month, experts from the United Nations, the World Bank and NGOs visited the area to study contingency plans for a breach of the Lake Sarez dam. (Soviet-era early-warning systems are no longer effective.) A dam collapse is unlikely but one possible scenario would involve 30-m-high waves surging over the top, triggering landslides that would affect up to 100,000 villagers.
THIS WEEK'S TABLE OF CONTENTS
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n o t e w o r t h y
THREE LITTLE ENVIRO-PIGS Canadian researchers say they have genetically engineered a cleaner strain of Yorkshire pigs. The modified porkers produce 20% to 50% less phosphorous in their manure, according to researchers at Ontario's University of Guelph. Phosphorous, when it enters streams and rivers, promotes the growth of algae and depletes water of oxygen needed to support fish and aquatic life. Low-phosphorous pigs will allow pork producers to comply with strict environmental regulations--and, at the same time, increase their herds by up to 50%.
THIS LAND IS YOUR LAND Since most endangered species in America live on privately owned land, the U.S. Fish and Wildlife Service has changed its rules to encourage landowners to help protect them. In the past, many were reluctant to alter part of their property to accommodate a certain species because they feared new restrictions could be imposed on the use of land if the species adapted well to their habitat. The new rules allow owners to change their land back to its original state after an agreed-upon time.
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