Science News

Thursday, April 1, 1999
Just Let Her Fly Shannon Lucid, a biochemist and NASA astronaut, holds the record for the most hours in orbit by a woman. In 1996 she was awarded the Congressional Space Medal of Honor by President Clinton, the only woman so honored. For six months aboard Russia's Mir space station in 1996, she grew wheat, monitored gestating quail eggs, and studied how fluids behave in space. We caught up with her at NASA's Johnson Space Center in Houston, where she helps train crews for the International Space Station.

What inspired you as a child to become a scientist? I wanted to know everything about the world around me. I decided to become a chemist when I read that water was composed of oxygen and hydrogen. I could not understand how two gases made a liquid.

What is your fantasy career? To be a great writer.

What do you think is the biggest problem facing the world today? The widening gulf between the haves and the have nots. The people who have access to resources get more and more, and the people who don't are getting less and less.

What are you reading now? A People's Tragedy: The Russian Revolution 1891-1924, a book by Orlando Figes.

If you could visit another planet, which would it be? Mars, because it's similar to Earth in a lot of respects, except that as far as I know it doesn't have life. Also, there's a reasonable chance that you can go there someday.

What is your greatest fear? To have nothing to read.

Did you take any books to Mir? I read about 50 books while I was up there, including several by Dickens--among them David Copperfield and Bleak House.

What else did you do to relax? We joked. And I liked watching Earth as the daylight passed.

If you could redesign the human body, what would you add? Wings.

If you were able to travel back in time, what era would you choose? Right now is the best time for a woman to live.

=========================================================Death Flares Yale astronomer Bradley Schaefer has some interesting news for those of us who live on Earth. He recently discovered that several nearby stars that closely resemble our sun can become violent, shooting off flares powerful enough to fry a planet more than a billion miles away. "These things are 100 to 10 million times larger than the biggest solar flares ever seen," Schaefer says.

A quirk of cosmic architecture apparently saves us from such fires. Schaefer's Yale colleague Eric Rubenstein theorizes that the magnetic field of a large planet orbiting close to a star may cause the flares. The planet's field could become entangled with the star's own magnetic field. When the twisted fields snap apart, the stored energy is released in one tremendous burst, creating what Rubenstein and Schaefer call a superflare.

The planet closest to our sun is tiny Mercury, which has a very weak magnetic field. But if Jupiter occupied Mercury's orbit, we'd be in trouble. Schaefer says Jupiter would then be in a position to trigger a gargantuan flare that would turn winter into summer on Earth and strip away the atmosphere's protective ozone layer. "Ultraviolet radiation would bathe the entire globe, causing the food chain to die from the bottom up," he says. "I wouldn't want to be around."

========================================================= More of That Asteroid's Dark Legacy The asteroid that hit the Caribbean basin 65 million years ago might have made Earth the most beautiful planet in the solar system. Researchers say the impact--thought to have devastated the planet's surface and ended the dinosaurs' long reign--may have lofted billions of tons of debris into orbit, leaving Earth with a Saturn-like ring.

The ring would have taken about a hundred thousand years to form, says University of New Mexico climatologist Peter Fawcett. Eventually, after 2 million or 3 million years, as the orbiting debris fell to Earth and burned up in the atmosphere, the ring would have disappeared. While it lasted, says Fawcett, it would have wreaked havoc with climate--and with whatever life survived the impact. Fawcett and Mark Boslough, a physicist at Sandia National Laboratories, made computer simulations that showed the ring would have cast a deep shadow on the ground, much like a total solar eclipse. The size and location of the shadow would have varied with the seasons.

The biggest shadow, more than 650 miles wide, would have fallen in the Northern Hemisphere on December 21, darkening a swath across Mexico, the Caribbean, and the Sahara Desert; on June 21 the Southern Hemisphere would have been under maximum shadow.

"The shadow would have turned warm tropical rain forests into colder, temperate regions--and that would have put a huge amount of stress on life," Fawcett says. "Life would have had to adapt--and then adapt again when the ring went away."

========================================================= Lion-Lizard Combo Found Peter Ward has unearthed some dramatic fossils in his day but nothing quite like the one he found late last year in South Africa. Ward's discovery--the first complete skeleton of a 250-million-year-old beast called a gorgon--resembled a cross between a lion and the fierce man-eating monitor lizard of Indonesia. The seven-foot-long fossil offers a detailed look at a predator that lived long before dinosaurs.

Until now researchers had found only skulls and a few scattered bones of gorgons--scant evidence that said little about what the animal's body looked like. Even their best guesses might have missed the mark, says Ward, a paleontologist at the University of Washington. The gorgon had a leonine, 2.5-foot-long head, 4-inch-long canines, and eye sockets on the sides of its skull.

The fossil hints at the fierce brutality of life in the late Permian Period. "Knowing how efficient the predators were gives us a better sense of what the prey was like," says Ward. A deadly predator like the gorgon would not have evolved without tough prey. That world ended 250 million years ago when a mysterious mass extinction--one far more severe than the catastrophe that killed the dinosaurs 185 million years later--wiped out gorgons, their prey, and 90 percent of most other life on Earth.

========================================================= Weather from Outer Space Cosmic rays--high-speed bits of atoms thought to be created by the blasts of exploding stars--bombard Earth's atmosphere constantly. Not many people besides physicists pay much attention to them, but that may soon change. A Danish physicist has found evidence that cosmic rays greatly influence Earth's climate, and may even trigger ice ages.

Henrik Svensmark of the Danish Space Research Institute was led to this idea while studying eras of climate change, including the little ice age, one of the most jarring shifts on record. From about 1300 to 1850, global temperatures plunged. Svensmark found that the most plausible explanation--changes in the sun's temperature--didn't hold up: they were too small.

Svensmark speculated that as cosmic rays streak through the atmosphere, they collide with atoms, creating reactions that help trigger cloud formation. Increased cloud cover would lower global temperatures by reflecting sunlight away from Earth's surface.

Fortunately for Svensmark, Earth preserves a record of this barrage. When cosmic rays hit carbon atoms in the atmosphere, they create radioactive carbon 14. The amount of carbon 14 in Earth's sediment layers thus reflects cosmic-ray bombardments throughout the centuries. During the little ice age, Svensmark says carbon 14 levels "went up by almost a factor of two."

========================================================= Here Comes the Plutonium Between 1956 and 1992 the United States exploded 828 nuclear bombs beneath the Nevada desert. Among the many radioactive elements created during those tests, one of the most deadly was plutonium. Just a millionth of an ounce of plutonium, if inhaled, greatly increases the risk of lung cancer. Many scientists assumed that because plutonium doesn't dissolve in water and binds strongly to rock, it hasn't moved an inch since it was blasted into the earth. That complacency was misguided, says geochemist Annie Kersting of Lawrence Livermore National Laboratory in California. She has found that plutonium drifts through groundwater by clinging to tiny suspended mineral particles.

Kersting studied water samples drawn from wells--a mile south of the site of a massive 1968 underground bomb test. She found traces of plutonium in the water that exactly matched the unique chemical signature of the element deposited at the bomb test site.

Kersting's find has disturbing implications. She says that at several Department of Energy facilities around the country, plutonium was dumped by injecting it directly into groundwater. "What people need to worry about," she says, "is how we're going to clean up the plutonium, and if it is moving at all these sites."

========================================================= Spinal Cord Cure? Unlike broken bones or torn ligaments, injured spinal cords never heal. "It's one of the great mysteries of neurobiology," says Richard Borgens of Purdue University. Such nerve damage invariably causes permanent paralysis, a grim prognosis that Borgens, a neurobiologist, hopes to change. He and physiologist Riyi Shi have managed to restore some function to the crushed spinal cords of guinea pigs.

The researchers treated the guinea pigs with a chemical called polyethylene glycol, applying it directly to the crushed parts of the animals' spinal cords. The chemical attracts water molecules and dehydrates membranes of nerve cells. Without water, the proteins in the membranes cluster together, "like soldiers closing ranks," says Borgens. This clustering seals tears at a cellular level and fuses damaged cells together. After a few minutes, Borgens adds water to the cells, restoring the membranes to normal.

Early results have been promising: of the dozens of guinea pigs tested, all regained some sensation and motor control. "Human trials," says Borgens, "could begin in a couple of years."

========================================================= Museum Review: The New York Hall of Science The New York Hall of Science has managed to harness a potent, nearly limitless source of energy: children. Realizing the futility of battling young metabolisms, the museum puts kids to work. In the rotunda, where a stationary bicycle is hooked up to an airplane propeller, not a moment goes by without some kinetic 12-year-old furiously pedaling and cooling off the whole building.

Set on the grounds of the 1964 World's Fair, the Hall of Science also allows children a respite from their labors. There's not a single do not touch sign in the museum. Children can poke, build, or take apart exhibits on molds, music, vision, and electricity. Starting April 1, the 30,000-square-foot outdoor playground will reopen with slides, windmills, and giant teeter-totters designed to teach basic Newtonian physics.

Inside the original World's Fair building--a glass-and-concrete cathedral to modernity--the museum hosts an exhibit on cinematic illusion until April 25. Special Effects 2 places visitors against exotic backdrops using big screens and computers. Not a bad show for anyone who longs to jump into a scene from Star Wars. Open 9:30 to 2. Monday through Wednesday, 9:30 to 5. Thursday through Saturday. Adults $6, children and seniors $4. Special Effects 2 is an additional $2.

========================================================= Why NASA Seems To Be Everywhere You Go NASA has ten centers scattered across the country:

  • Ames Research Center, Moffett Field, California: Ames conducts wind-tunnel tests and astrobiology research--the study of what life might be like on other worlds. Moffett Federal Airfield and the Software Independent Verification and Validation Facility in Fairmont, West Virginia--are Ames subsidiaries.
  • Dryden Flight Research Center, Edwards, California: develops everything from unmanned planes for environmental monitoring to next-generation launch vehicles.
  • Jet Propulsion Laboratory, Pasadena, California: the birthplace of Sojourner, Cassini, Galileo, and most other unmanned NASA space vehicles, JPL specializes in the robotic exploration of space. The labs network of bases in the Mojave Desert, Spain, and Australia communicate with spacecraft.
  • Johnson Space Center, Houston: mission control, where astronauts train in a giant pool to simulate spacewalking. JSC coordinates the development of the International Space Station. The White Sands Test Facility, in Las Cruces, New Mexico, is part of JSC.
  • Lewis Research Center, Cleveland: specializes in supersonic- and subsonic-engine design.
  • John F. Kennedy Space Center, Cape Canaveral, Florida: receives all the different pieces of a spacecraft, readies them for takeoff, and launches them.
  • Goddard Space Flight Center, Greenbelt, Maryland: manages satellites, with branches at Wallops Flight Facility in Virginia and the Goddard Institute for Space Studies in New York City.
  • Langley Research Center, Hampton, Virginia: develops new aircraft designs.
  • Marshall Space Flight Center, Huntsville, Alabama: research for manned space flight; development of main engines and solid rocket boosters.

  • John C. Stennis Space Center, Mississippi: tests propulsion systems for future space vehicles.

    ========================================================= Spin, Baby, Spin Inventors Jack Bitterly and his son Steve of U.S. Flywheel Systems in Newbury Park, California, want to run internal-combustion engines off the road. They would rip out everything beneath a car1s hood‹engine, battery, and radiator‹and replace them with about a dozen 50-pound, carbon-fiber flywheels, each spinning 100,000 times per minute. After the Bitterlys were featured in our August 1996 issue, they had to shelve their plans to develop a flywheel-powered prototype car because no auto companies were interested. So they turned to building flywheels to replace chemical batteries on the International Space Station. They expect to see flywheels in satellites by 2002.
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