Strongest solar storm in 20 years puts on a light show

The strongest solar storm in more than two decades struck Earth on Friday, triggering spectacular auroras worldwide.

According to the US National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center, the first of several coronal mass ejections (CME) occurred shortly after 1600 GMT.

It was later upgraded to an "extreme" geomagnetic storm. It was the first such storm since the Halloween storms of October 2003, which caused blackouts in Sweden and damaged power infrastructure in South Africa.

The green and blue lights — which are expected to continue for a few days — were seen from Britain to Tasmania, with officials in the US saying sightings might be possible as far south as Alabama and Northern California.

Meanwhile, people from all over Germany posted photos of the aurora on social media. Scientists say the best views of the aurora may come from cell phone cameras, which are better at capturing light than the naked eye.