GAMMA-RAY BURST MYSTERY SOLVED?
California Institute of Technology researchers believe they have solved the mystery of gamma-ray bursts, the gigantic blasts of lethal radiation that release the energy of billions of suns. The culprits, CalTech researchers said, are supernovae, the explosions of dying stars. The finding was obtained from a gamma-ray burst detected last November and studied by the Hubble Space Telescope and several Earth-based instruments. Careful observations of the burst -- called GRB 011121 -- have uncovered remnants of an exploded star, whose signature data were found buried within the burst's fading embers. Earlier observations have hinted that gamma-ray bursts result from supernovae, but the evidence has been inconclusive. This time, there seems to be no doubt, researchers said, because supernovae produce specific effects that would be difficult to create by other means.
ELEVEN MORE JUPITER MOONS
In a planetary case of "carrying coals to Newcastle," an international team of astronomers has confirmed 11 more moons orbiting Jupiter. Using the Canada-France-Hawaii telescope on Mauna Kea in Hawaii, plus one of the largest digital imaging cameras in the world, and high-speed computer processing, as well as supplementary observations to rule out asteroids masquerading as satellites, the team has confirmed the newest members of the Jovian system. The 11 objects all have retrograde orbits, meaning they circle Jupiter in a direction opposite the planet's rotation. They also are quite small, with diameters estimated between 1 and 3 miles. So far, nothing else is known about them, but the astronomers said the moons probably are little bits of rock left over from the formation of the solar system and captured by Jupiter's gravity. The new discoveries bring the known total of Jovian satellites to 39, of which only four are major objects -- Io, Europa, Callisto and Ganymede. They also put Jupiter back in the lead for satellites, because rival planet Saturn is known to have only 30.
RAINFALL CHANGES HELP PLANTS ABSORB CARBON
Changing rainfall patterns over much of the United States in the last century have allowed plants to grow more aggressively and absorb more carbon dioxide from the atmosphere, University of Montana researchers report. Scientists have noticed the U.S. carbon sink -- an effect that drains carbon from the air and stores it in the land -- began increasing in the latter part of the 20th century. Earlier research claimed this trend was due to reforestation, as well as greater concentrations of atmospheric CO2 and warming temperatures. But the UM study suggests changing rainfall patterns may be playing a bigger role in plant growth and carbon absorption. Computer models show, on average from 1950 to 1993, higher humidity combined with an 8 percent increase in rainfall has led to a 14 percent increase in U.S. plant growth. The data also show increases in cloud cover, minimum temperatures, soil moisture and stream flows -- all signs of a changing rainfall cycle.
AND NOW ... SPINTRONICS
Physicists at the State University of New York at Buffalo report they have created new semiconducting materials that could be developed into "spintronic" devices. Spintronics is an emerging technology that uses the spin of electrons as well as their charge. This represents a huge potential advance in computers, because instead of relying on one of two binary digits to encode information, spintronics could process data using a nearly infinite variety of electron spin states. For example, this property would allow computers to process millions or billions of bits of information instantly, while conventional machines would have to sift through the data bits one at a time. UB researchers said the technology might also lead to the development of quantum computers -- ultra-small, ultra-fast devices that are still just theoretical.
(Editors: For more information on BURSTS, contact Robert Tindol at 626-395-3631 or [email protected]. For MOONS, David Jewitt at 808-956-7682 or [email protected]. For RAINFALL, Cynthia O'Carroll at 301-614-5563 [email protected]. For SPINTRONICS, Ellen Goldbaum at 716-645-5000 ext. 1415 or [email protected])
