
© Joseph Bradley of Whitehorse, Yukon, CanadaAuroras in the aftermath of a near-Earth magnetic explosion on Dec. 20, 2015.
From the always excellent
spaceweather.com comes the news that on December 20, 2015, a powerful 'explosion' occurred closer to Earth than anyone had seen before.
It has taken researchers more than 4 years to fully wrap their minds around what happened, and their results were published just this week in the January 13, 2020 edition of
Nature Physics.
Explosions in Earth's magnetic field happen all the time, writes Dr. Tony Philips of
spaceweather.com. Gusts of solar wind press against Earth's magnetosphere, squeezing lines of magnetic force together. The lines crisscross and reconnect, literally exploding and propelling high energy particles toward Earth — auroras are the afterglow of this process.
"Usually, these explosions happen at least 100,000 miles from Earth, far downstream in our planet's magnetic tail," explains the study's lead author Vassilis Angelopoulos of UCLA.
"On December 20, 2015, however, we observed a reconnection event only 30,000 miles away-more than 3 times closer than normal."The discovery was a case of good luck and perfect timing.
Comment: Weird 'electrical surge' detected running through ground in northern Norway - Auroras follow