Equinox Auroras

Equinox Auroras

 For reasons reseachers don't fully understand, auroras love equinoxes. At this time of year, even small gusts of solar wind can spark colorful lights around the poles. On Thursday, the aurora australis appeared over South Arm, Tasmania:

 

 

"I captured this image from Betsey Island," says photographer Luke O'Brien. "This is a 30 second exposure at ISO 2500. "

The solar wind blowing past Earth today is relatively slow, only ~350 km/s. As a result, NOAA forecasters estimate a slim 5% chance of polar geomagnetic storms. That might be enough, however, for more equinox auroras.