The most powerful solar storm in more than two decades was responsible for spectacular celestial light shows in skies from Tasmania to Britain — and threatening possible disruptions to satellites and power grids — with the Bureau of Meteorology predicting more to come.
The first of several coronal mass ejections (CMEs) — expulsions of plasma and magnetic fields from the sun — came just after 1600 GMT on Friday (2am Saturday AEST), according to the United States' National Oceanic and Atmospheric Administration (NOAA)'s Space Weather Prediction Center.
The northern lights glow in the night sky above the village of Daillens, Switzerland. Source: AAP / Laurent Gillieron/EPA
The aurora borealis glow in Merseyside, England. Source: AAP / Peter Byrne/PA
Social media lit up with people posting pictures of auroras borealis and australis from Australia and northern Europe.
Authorities notified satellite operators, airlines and the power grid to take precautionary steps for potential disruptions caused by changes to Earth's magnetic field.
Officials said people should have the normal backup plans in place for power outages, such as having flashlights, batteries and radios at hand.
Where can I see Aurora Australis?
On Saturday, the Bureau of Meteorology's Australian Space Weather Forecasting Centre said it had issued a warning that morning indicating a chance of G5 (extreme) geomagnetic storm conditions.
The largest solar storm since 2003 causes Aurora Australis, The Southern Lights, to be visible in Melbourne and across Southern Australia. Source: SIPA USA / Alex Zucco/SIPA
On Sunday, the Bureau said that it had observed a geomagnetic storm event over the previous 24 hours, resulting in "amazing images of Aurora Australis".
People visit St Mary's lighthouse in Whitley Bay, England to see the aurora borealis. Source: Getty / Ian Forsyth
The Bureau said that while current planetary geomagnetic conditions are at the G3 (strong) level, geomagnetic conditions within Australia are currently lower at G1 (minor conditions).
Aurora Australis in Melbourne. Source: SIPA USA / Alex Zucco/SIPA
The Northern Lights appear in the night sky over East Brandenburg. Source: AAP / Patrick Pleul/AP
Unlike solar flares, which travel at the speed of light and reach Earth in around eight minutes, CMEs travel at a more sedate pace, with officials putting the current average at 800km per second.
They emanated from a massive sunspot cluster that is 17 times wider than our planet. The sun is approaching the peak of an 11-year cycle that brings heightened activity.
