'Corona' auroras taken on September 4, 2020 @ Utsjoki, Finnish Lapland
© Rayann Elzein'Corona' auroras taken on September 4, 2020 @ Utsjoki, Finnish Lapland
Last night, a special type of aurora appeared over Finland. It was a "corona"--a form of Northern Lights that rains down from directly overhead. Rayann Elzein happened to be looking straight up when the outbreak occurred.

"This corona 'exploded' overhead and continued blinking and displaying fast needles for several minutes!" says Elzein. "What a fantastic and unexpected night up here in Utsjoki!"

The display coincided with a sudden negative dip in BsubZ. In other words, a crack opened in Earth's polar magnetic field. Solar wind poured in to fuel the display.

More coronas are in the offing. During weeks around equinoxes, cracks in Earth's magnetic field become common--a phenomenon known as the Russell-McPherron effect. With the northern autumnal equinox less than three weeks away, the space weather forecast calls for geomagnetic rain.