Auroras exploded on Feb. 22 2018

On Thursday, Feb. 22, 2018, a solar wind stream grazed Earth's magnetic field.
The off-center impact of the solar wind caused something unusual to happen. Earth's polar magnetic field rang like a bell. Rob Stammes recorded the phenomenon from his magnetic observatory in Lofoton, Norway: "On Feb. 22nd, the magnetic field around our observatory (as measured by ground currents) was swinging back an forth with a 100 second period," says Stammes. "This very stable oscillation went on for more than an hour."

Researchers call these pure ultra-low frequency oscillations "pulsations continuous" (Pc).