WEAK INTERPLANETARY SHOCK SPARKS AURORAS

WEAK INTERPLANETARY SHOCK SPARKS AURORAS

An interplanetary shock wave, origin unknown, hit Earth's magnetic field during the late hours of May 7th. Although the weak impact did not spark a geomagnetic storm, solar wind conditions in the wake of the shock have been favorable for auroras. Nancy Dean took this picture last night on Mount Spur, Alaska:

 

"The sunset was still showing strong on May 8th when the Northern Lights came out to dance across the Alaskan sky," says Dean.

As northern spring unfolds, persistent twilight is spreading into the night skies of Alaska. It takes a bright display of auroras to be seen against such a backdrop. Dean's photo is evidence that a weak shock does not necessarily produce weak auroras.

More lights are possible tonight. NOAA forecasters estimate a 30% chance of polar geomagnetic storms as Earth exits the wake of the shock.

From SpaceWeather.com