IN THE NEWS - Scientific - http://maxpages.com/stargate/Astronomy

Death Flares
Yale astronomer Bradley Shaefer has some intresting news for those of us who live on Earth. He has 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 aways. "These things are 100 to 10 million times larger than the biggest solar flares ever seen," Schaefer says.

A quirk cosimc architecture apparently saves us from such fires. Shaefer's Yale colleague Eric Rubenstein theorizes that the magnetic field of a large planet orbiting close to a star may cause 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."
-Discover Magazine

More Of That Asteriod's Dark Legacy
The asteriod 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, amde a 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 Nothern 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."
-Discover Magazine

NASA'S ASTEROID HUNTERS NET A SURPRISE CATCH
Astronomers searching for asteroids headed toward Earth have stumbled upon a harmless but fascinating discovery--an exploding star, also known as a supernova.

The supernova, named 1999am, is located in a galaxy about
650 million light-years away. (A light-year is the distance
light travels in one year, about 9.5 trillion kilometers or 6 trillion miles.) The star was unknown to astronomers until it was captured by the camera on NASA's Near Earth Asteroid Tracking (NEAT) system on February 18. The NEAT images show the star as it looked just a few weeks after the ancient explosion took place.

"We were fishing for salmon, and instead we caught a whale,"
said Dr. Steven Pravdo, project manager and co-investigator for NEAT. "The project is designed to look for asteroids and other objects that might pose a potential hazard to Earth. This supernova discovery is an added bonus for astronomers in general."

Supernova 1999am is a "Type Ia supernova," which means that
before it exploded, it was a white dwarf star in orbit with a companion star. Near the end of its life, the white dwarf
captured so much material from its companion that it became too massive to support itself, and exploded with as much energy as 100 billion suns. 1999am is now nearly as bright as the galaxy surrounding it, which is known as CGCG 060-009.

NEAT, with asteroid hunter Eleanor Helin as principal
investigator, has been in operation since December 1995.It uses a large, sensitive and fully automated charge-coupled device (CCD) camera mounted on a 1-meter-diameter (39-inch) telescope. The telescope is operated by the U.S. Air Force atop Mt. Haleakela on the island of Maui, HI.

Since the middle of 1998, NEAT scientists have posted their
data on a web site through a program called SkyMorph, a
collaboration between JPL and NASA's Goddard Space Flight Center, Greenbelt, MD. While the NEAT project detects Earth-approaching objects by looking for celestial bodies that move over a period of time, the data can be used also to hunt for stationary objects that become brighter or dimmer over time. Thus, the images present a smorgasbord of astronomical options--NEAT scientists pick out asteroids, while other astronomers select various cosmic morsels through the public SkyMorph web site.

"Through SkyMorph, astronomers may find an array of
interesting objects, including supernovae," said Pravdo,
principal investigator for SkyMorph."In this case, we sent our data directly to the Lawrence Berkeley National Laboratory in Berkeley, California. Dr. Greg Aldering and other scientists with their Supernova Cosmology Project immediately found 1999am."

Pravdo said the Lawrence Berkeley National Laboratory
scientists found the supernova by comparing images taken in
February with previous NEAT data. They could clearly see a
change in brightness, indicating the star had exploded and become a supernova. They further confirmed their finding with additional observations by ground-based telescopes. February 18 marked the first time NEAT scientists forwarded new data directly to the Berkeley lab, and as Pravdo pointed out, "We struck paydirt."

For information and an image of 1999am, go to the following web site:http://huey.jpl.nasa.gov/~spravdo/snanima.htm

For more information on the NEAT project go to
http://huey.jpl.nasa.gov/~spravdo/neat.html

Information on SkyMorph is available at the following web site:http://skys.gsfc.nasa.gov/skymorph/skymorph.html
-JPL

EXPERIMENT LAYS GROUNDWORK FOR 'LIVING OFF THE LAND' ON MARS
NASA engineers have succeeded in a realm often left to alchemists and magicians -- creating something valuable "out of thin air." In this case, the thin air was a simulated Martian atmosphere, and the valuable commodity was oxygen.

"The concept is to use the resources on Mars to reduce
the amount of material that needs to accompany a human mission...to 'live off the land,'"said David Kaplan, principal investigator of the Exploration Office at NASA's Johnson Space Center, Houston, Texas. "Producing oxygen using materials readily available on Mars would be an important step toward reducing the costs and risks of an eventual human mission to Mars."

This week's demonstration is an initial test of technology that will be aboard the Mars Surveyor 2001 Lander, scheduled to launch April 10, 2001, and land on Mars on January
22, 2002. Called the Mars In-Situ Propellant Production
Precursor, the experiment will test the feasibility of using the thin Martian atmosphere to produce oxygen for breathing air and propellants. Propellants created on Mars could eventually be used to send samples and astronauts back to Earth.

"The oxygen production technology being tested this week is
based on sound, straightforward chemistry," said Jerry Sandersof Johnson's Propulsion and Fluid Systems Branch.

The primary test involves an experimental device inside
a Mars environment chamber that selectively absorbs carbon dioxidefrom a simulated Martian atmosphere -- called "Mars mix" -- and converts it to oxygen. This technology also may be used to extractpure oxygen from Earth air for home, medical and military needs.

The atmosphere inside the experiment chamber simulates
Martian temperatures and atmospheric pressures. The "Mars mix" is 95 percent carbon dioxide, thin (almost 150 times thinner than Earth's atmosphere) and cold (-75 degrees Centigrade, -105 degrees Fahrenheit) like a typical Martian night.

The mix provides the feedstock for the chemical reaction.
A wafer-thin, solid-oxide ceramic disk made of zirconia, about the size of a small cookie, is sandwiched between two platinumelectrodes and heated to 750 degrees Centigrade (1,380 degreesFahrenheit). When carbon dioxide is fed to this unit, the zirconia cell "cracks" the carbon dioxide into carbon monoxide and oxygen.Only the oxygen can penetrate through to the other side of the disk; the carbon dioxide and carbon monoxide gases are stopped in their tracks.

The Mars Surveyor 2001 Lander is expected to provide essentialinsights into how to conduct successful, cost-effective human missions to Mars. The lander's primary science goal is to explore the mineralogy of the landing site, near the Martian equator,by taking visible and infrared pictures of the surrounding terrain and deploying a rover similar to Mars Pathfinder's Sojourner. Other
equipment will analyze the Martian soil and surface radiation.

The Mars In-Situ Propellant Production Precursor demonstrationis part of Johnson's continuing effort to identify solutions to the challenges facing future human explorers of other worlds. The Johnson Space Center is NASA's lead center for the Human Exploration and Development of Space enterprise.
-JPL

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