A CME hit Earth's magnetic field on Oct. 24th at approximately 1800 UT (02:00 pm EDT). According to analysts at the Goddard Space Weather Lab, the impact caused a strong compression of Earth's magnetic field, allowing solar wind to penetrate all the way down to geosynchronous orbit for a brief period between 19:06 UT and 19:11 UT. Earth-orbiting spacecraft could have been directly exposed to solar wind plasma during that time.

The impact also sparked a geomagnetic storm, underway now. Geir Øye sends this picture from Ørsta, Norway:

Geomagnetic Storm
© Geir Øye
"These are the strongest and most beautiful auroras I've ever seen," says Øye, a veteran observer of Northern Lights. "I can only imagine what the display must have been further north."

High-latitude sky watchers should remain alert for auroras as Earth's magnetic field continues to reverberate from the CME impact. The best time to look is usually during the hours around local midnight.

More Images:
From Viljo Allik of Tartu, Estonia; from Göran Strand of Frösön, Sweden; from Janis Satrovskis of Burtnieki, Latvia; from Geir Øye of Ørsta, Norway; from Christian Praetorius of Lake Kleifarvatn, Hafnarfjördur, Iceland; from Matti Aladin of Helsinki, Finland; from Ivar Marthinusen of Trondheim, Norway; from Göran Fredriksson of Örnsköldsvik, Sweden; from Petra Schneider of Hafnarfjördur, Iceland; from Ronny Tertnes of Bergen, Norway;

Magnetic Data:
From Dave Gradwell of Birr Ireland; from Rob Stammes of Laukvik, Lofoten, Norway