Health & Science

The stuff of life on Mercury

Mercury, the closest planet to the sun, has blistering 800-degree temperatures at its equator—but its poles are full of ice. New data from NASA’s Messenger spacecraft, which began orbiting Mercury last year, has revealed that as much as a trillion tons of ice exists in shadowy polar craters, where temperatures can drop to minus 370 degrees. Much of the ice appears to be covered in carbon-based organic compounds—some of the “same ingredients that may have led to life on Earth,” UCLA planetary scientist David Paige tells Reuters.com. Millions of years ago, icy asteroids and comets collided with Mercury, seeding the planet with ice and organic compounds—the same process, scientists believe, that made Earth a watery planet. Mercury’s environment has long been considered too hostile for life, but the new observations have raised the question of whether any regions on or within Mercury might have both liquid water and organic compounds. Somewhere between the poles and the equator, Mercury might have milder regions that are more hospitable, especially just below its surface. Researcher Maria T. Zuber, of the Massachusetts Institute of Technology, said it’s not likely that life exists on Mercury, but the fact that even such an inhospitable planet contains both water and organics “raises the possibility that life could occur someplace else.’’

A tap water danger?

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Chemicals used to purify tap water may be causing food-allergy rates to skyrocket in the U.S., a new study suggests. Researchers at the Albert Einstein College of Medicine tested the urine of more than 2,000 people for dichlorophenols, chemicals found in chlorine-treated tap water and in pesticides used on many fruits and vegetables. They found that people with the highest levels of dichlorophenols in their bodies were 80 percent more likely to have food allergies—most commonly to eggs, milk, peanuts, wheat, soy, and shellfish—than those with the lowest levels. Over the past 15 years, food-allergy rates have increased nearly 20 percent in the U.S.; more than 3 million children younger than 18 have allergies with reactions that range from mild to deadly. “While the study does not allow concluding that pesticides are responsible for the allergies, it certainly raises the possibility,” Kenneth Spaeth, an expert on environmental pollutants at North Shore University Hospital on Long Island, N.Y., tells ABCNews.com. Researchers think that Americans’ increased exposure to dichlorophenols may be killing off healthy bacteria in the gut that help the immune system function properly, causing it to attack otherwise harmless proteins in food.

A rift over the Grand Canyon

Have geologists been all wrong about how the Grand Canyon was created, and when? That’s the implication of a new study that estimates the canyon’s age at 70 million years, instead of 6 million, The New York Times reports. Researchers from the University of Colorado used advanced dating techniques to calculate the age of a mineral called apatite found in rocks in the canyon. Their measurements suggest that it wasn’t the west-flowing Colorado River that carved the canyon, but “an ancient Cretaceous river that flowed eastward from western highlands.” That would mean that the last of the dinosaurs, which became extinct around 65 million years ago, might have gazed into the now 277-mile-long chasm. If they did, they would have seen not “the starkly beautiful desert of today but an environment with more lush vegetation,” says University of Maryland paleontologist Thomas Holtz. But other experts who have studied canyon sediments insist that the Colorado eroded the gorge far more recently. University of New Mexico geologist Karl E. Karlstrom calls the idea that the Grand Canyon existed during the dinosaur age “ludicrous.”

Africa’s disappearing lions

Africa’s lions are dwindling toward extinction at an alarming rate, Duke University researchers say. Using new high-resolution satellite data from Google Earth, they’ve discovered that the savanna habitat that lions need to survive has shrunk by 75 percent over the past 50 years and is far more fragmented than conservationists previously realized. Over the same period, the lion population is thought to have declined by two thirds, from 100,000 animals to fewer than 35,000. “Those in West Africa are in particularly bad shape,” study author Stuart Pimm tells NBCNews.com; fewer than 500 lions remain there, where the human population has doubled in the last three decades. Only about 24,000 African lions live in areas where they have space to roam and are safe from hunters—including farmers who often kill them to protect their livestock. Elsewhere, the species is at risk of disappearing. The “stunning and grim” discovery that Africa’s savannas—and lions—are nearly gone, says Thomas Lovejoy, a conservationist at George Mason University, “emphasizes the urgency for conservation of these great habitats.”