Wow!!!
An interplanetary shock wave, possibly the leading edge of a CME, hit Earth's magnetic field on October 8th at approximately 2015 UT. The impact sparked a G1-class geomagnetic storm and bright auroras around the Arctic Circle. Harald Albrigtsen sends this picture from Tromsø, Norway:
"This is a 10s exposure at ISO 1600," he says. Novice aurora photographers who wish to take similar pictures may find more photo settings here.
http://spaceweathergallery.com/indiv_upload.php?upload_id=87613Solar wind speeds remain elevated (~450 km/s) as Earth exits the wake of the CME. As a result, NOAA forecasters estimate a 40% chance of polar geomagnetic storms on Oct. 10th.
