Damn, I thought it was caused by magic. Jim Wiley-2 wrote: > > I thought all you Elecrafters out there would find this interesting: > > > > Mystery of northern lights revealed > > > > SATELLITES: Magnetic explosions in space trigger the dancing displays. > > By MARCIA DUNN > The Associated Press > > > CAPE CANAVERAL, Fla. -- Scientists have exposed some of the mystery > behind the northern lights. > > > On Thursday, NASA released findings that indicate magnetic explosions > about one-third of the way to the moon cause the northern lights, or > aurora Borealis, to burst in spectacular shapes and colors, and dance > across the sky. > > > The findings should help scientists better understand the more powerful > but less common geomagnetic storms that can knock out satellites, harm > astronauts in orbit and disrupt power and communications on Earth, > scientists said. > > > A fleet of five small satellites, called Themis, observed the beginning > of a geomagnetic storm in February, while ground observatories in Canada > and Alaska recorded the brightening of the northern lights. The southern > lights -- aurora Australis -- also brightened and darted across the sky > at the same time. > > > These auroral flare-ups occur every two or three days, on average. > > > A team led by University of California, Los Angeles, scientist Vassilis > Angelopoulos confirmed that the observed storm about 80,000 miles from > Earth was triggered by a phenomenon known as magnetic reconnection. > Every so often, the Earth's magnetic field lines are stretched like > rubber bands by solar energy, snap, are thrown back to Earth and > reconnect, in effect creating a short circuit. > > > It's this stored-up energy that powers the northern and southern lights > or, in other words, causes them to dance, according to Angelopoulos. > > An opposing theory has these geomagnetic events occurring much closer to > Earth, about one-sixth of the way to the moon. More Themis observations > are needed to resolve the debate, said David Sibeck, NASA's project > scientist. > > > "Finally, we have the right instruments in the right place at the right > time, and it's allowed scientists to be able to make the necessary > observations to settle this heated debate once and for all," said Nicola > Fox, a Johns Hopkins University scientist who was not involved in the > study. > > > At present, about 20 of these geomagnetic storms are being analyzed. > Scientists hope to eventually learn, via this project, more about the > bigger solar storms that occur about 10 times a year and can lead to far > more expansive and prolonged northern and southern lights. > > > The five Themis spacecraft -- a NASA acronym standing for Time History > of Events and Macroscale Interactions during Substorms -- were launched > aboard a single rocket last year. > > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > >
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