WASHINGTON, United States (AFP) — The most powerful solar storm in more than two decades struck Earth on Friday, triggering spectacular celestial light shows from Tasmania to Britain — and threatening possible disruptions to satellites and power grids as it persists into the weekend.

The first of several coronal mass ejections (CMEs) — expulsions of plasma and magnetic fields from the Sun — came just after 1600 GMT, according to the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center.

It was later upgraded to an “extreme” geomagnetic storm — the first since the “Halloween Storms” of October 2003 caused blackouts in Sweden and damaged power infrastructure in South Africa. More CMEs are expected to pummel the planet in the coming days.

Social media lit up with people posting pictures of auroras from northern Europe and Australasia.

“We’ve just woken the kids to go watch the Northern Lights in the back garden! Clearly visible with the naked eye,” Iain Mansfield in Hertford, England, told AFP.

That sense of wonder was shared in Australia’s island state of Tasmania.

“Absolutely biblical skies in Tasmania at 4 a.m. this morning. I’m leaving today and knew I could not pass up this opportunity,” photographer Sean O’ Riordan posted on social media platform X alongside a photo.