Gamma Rays from Severe Weather

[GACarlson@aol.com]

Complete article is at 
http://science.msfc.nasa.gov/newhome/headlines/essd26may99_1.htm

What Comes Out of the Top of a Thunderstorm
Gamma Rays from Severe Weather

May 26, 1999: Springtime in North America often brings severe weather such as 
tornadoes, thunderstorms, high winds, and damaging hail. But just as powerful 
and fascinating as what comes out of the bottom of storm clouds are the 
flashes of gamma-rays that have been observed coming out of the top.

Terrestrial gamma-ray flashes (or TGFs) are short blasts of gamma-ray energy 
associated with  thunderstorms. They only last a few milliseconds - about as 
long as the sound from a snap of the fingers - and can only be detected by 
satellites orbiting the Earth. NASA scientists inadvertently discovered TGFs 
while they were monitoring bursts of gamma-ray energy coming from the depths 
of space.

"Like so many things in science, we came across these (TGFs) totally by 
accident," commented Dr. Jerry Fishman, principal investigator on the Burst 
and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray 
Observatory. "We designed BATSE to collect gamma-rays from the deepest 
recesses of space, which it does very well. What we didn't know it would do 
was also collect gamma rays released from severe weather systems on Earth."
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