From: nasanews
Date: Dec 7 20:20 UTC
Subject: Gamma Ray Flashes Common
GAMMA RAY FLASHES IN ATMOSPHERE MORE COMMON THAN THOUGHT
Scientists at NASA's Marshall Space Flight Center in Huntsville, AL,
are observing rare gamma ray flashes above thunderstorms at a rate six
times that of previous observations.
The observations are being made by the Burst and Transient Source
Experiment aboard NASA's Compton Gamma Ray Observatory which was
recently modified by ground commands to be more sensitive to the
events.
"The high rate of occurrence of these gamma ray events suggests the
presence of a little understood, but significant phenomena that will
have impact in many scientific fields," explained Dr. Steve Goodman of
Marshall's Space Sciences Laboratory. "We're especially looking forward
to the opportunity to bring together investigators from the fields of
space and atmospheric physics to study these newly discovered events."
Scientists previously observed gamma ray flashes above thunderstorm
activity about once every six weeks. Now, they are observing such gamma
ray events weekly. The first indications of gamma ray flashes above
thunderstorms were detected by the Burst and Transient Source
Experiment earlier this year.
It is suspected the gamma ray flashes come from a rare type of powerful
electrical discharge, similar to lightning, above large thunderstorm
regions. The observed flashes are very brief, lasting only a few
thousandths of a second. In the past two months most of the observed
gamma ray flashes have occurred near the equator, primarily over
regions of South America and the East Indies known to have high
thunderstorm activity.
These recent observations have been confirmed by other instruments on
the Compton Observatory. The gamma ray observations from the Earth's
atmosphere and their association with thunderstorms is a complete
surprise to scientific investigators. It is suspected the gamma ray
events may be related to faint, but visible electrical discharges
observed and reported recently high in the stratosphere above
thunderstorms.
The new observations were presented at a meeting of the American
Geophysical Union in San Francisco today by Dr. Steve Goodman. The
Compton Gamma Ray Observatory is managed by NASA's Goddard Space Flight
Center in Greenbelt, MD, and the Burst and Transient Source Experiment
is managed by Marshall.
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- T o d d E. V a n H o o s e a r -
``'''vanhoose@lalaland.cl.msu.edu - vanhoose@msu.edu - vanhoose@lalaland.cl.msu.edu
(._.) Michigan State University - East Lansing, MI USA
(_) Computer Laboratory - Department of Communication
`---' <A HREF="http://lalaland.cl.msu.edu/~vanhoose/">My Home Page</A>
"I'd love to change the world, but they won't give me the source code!"
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