No geomagnetic storm was in the forecast for Sept. 19th, but a
storm occurred anyway. Sky watchers around the Arctic Circle saw the midnight
sky turn green as magnetometers registered an unexpected G1-class
disturbance between 0300 and 0600 UT. "Suddenly there were lots of
Northern Lights above the Lofoten Islands of Norway," reports Eric Fokke,
who put his camera on the ground to record the display through a patch of
there was no Moon to illuminate the mushroms, so I had to take this picture
under streetlights," says Fokke. "The auroras were bright enough to
see despite the manmade glare."
The source of
the display was a fluctuation in the interplanetary magnetic field (IMF).
During the early hours of Sept. 19th, the IMF tipped south, opening a
crack in our planet's magnetosphere. Solar wind poured in to fuel the storm.
forecasters estimate a 20% chance of more polar geomagnetic storms tonight. In
other words, if you're an Arctic photographer, there's a 1 in 5 chance you
should find a pumpkin patch.