Fears of disruption as big solar storm strikes the Earth

Prof Cally from Monash University in Australia explains what will happen when the solar storm hits

The Earth is currently being battered by a storm of charged particles from the Sun, which could disrupt power grids, satellite navigation and plane routes.

The storm - the largest in five years - will bombard the Earth's magnetic field throughout Thursday.

It was triggered by a pair of solar flares - the largest of their kind - earlier this week. As a result, the Northern Lights may be visible at lower latitudes.The effects will be most intense in polar regions, and aircraft may be advised to change their routings to avoid these areas.

In the UK, the best chance to see them will be on Thursday night, the British Geological Survey says. The Sun's activity rises and falls through an 11-year cycle, and has in recent months been seen to launch more of the solar flares that are causing the current storm.

The cycle is due to peak in 2013. The flares have resulted in what is known as a coronal mass ejection, "the technical term for what is really just a big ball of gas travelling at 2,000 kilometres per second", according to Doug Biesiecker from the US National Oceanic and Atmospheric Administration (Noaa).

The incoming cloud of charged particles could affect satellites and will launch a geomagnetic storm in the Earth's protective magnetic field, Mr Beisiecker told the BBC. "This magnetic field keeps harmful radiation out. Now, the geomagnetic storm isn't going to take that magnetic field away from the Earth, but... it's going to shake it and if you shake a magnetic field you generate things like electric currents in the atmosphere and say, in the power grid that criss-crosses pretty much every country on the planet now."

Dr Craig Underwood, from the Surrey Space Centre, UK, said: "The event is the largest for several years, but it is not in the most severe class. We may expect more storms of this kind and perhaps much more severe ones in the next year or so as we approach solar maximum. "Such events act as a wake-up call as to how our modern western lifestyles are utterly dependent on space technology and national power grid infrastructure."

(Sources - http://www.bbc.co.uk)