And the forecast is … severe storm 93 million miles away, followed by death and destruction

FIRST it was giant meteorites hurtling towards Earth on a seemingly unstoppable path to Doomsday. Now, senior scientists at Nasa are warning of another cataclysmic force from the heavens about to decimate life as we know it.

• A 'perfect storm' of plasma and solar energy on a course to Earth at the speed of light could cause a global economic disaster. Picture: Getty

The sun, the scientists say, is awakening from a long and deep slumber and set to embark on a period of violent solar activity that could send devastating electromagnetic radiation racing to our planet.

One massive storm on the sun's surface, 93 million miles away, would be powerful enough to knock out power grids, destroy satellites controlling GPS and communications networks, ground airlines and throw the world's banking system into chaos.

The disruption to the fuel chain and subsequent breakdown in social order could leave governments powerless and tens of millions without clean water, access to medicines or fresh food, Nasa studies suggest.

If it sounds like the plot of Hollywood's latest apocalyptic movie, scientists are taking the threat seriously enough to have called government officials, disaster response managers, power company chiefs and other interested parties to a space weather forum in Washington DC yesterday.

"A storm of this magnitude would be a low probability event but would have a very high impact," said Chris St Cyr, a senior astrophysicist at Nasa's Goddard Space Flight Centre in Maryland.

"It might not happen as often as hurricanes, earthquakes or volcanic eruptions but we are more vulnerable than ever before. Now, we use satellites for mobile phones, navigation, communication, just running your Visa card through to make a purchase.

"Our power grids are interconnected and would act as one giant antenna in a big geomagnetic storm. There's a need to highlight to those in decision-making positions that this is a natural hazard that we didn't have to worry about in the 1970s, but now we do."

St Cyr's colleagues at Nasa's Heliophysics Science Division, which studies the sun's relationship with Earth and neighbouring planets, say solar activity runs in cycles averaging 11 years, with the next peak due in late 2012 into 2013.

"We have been in an extended phase of minimal activity, which typically lasts two to three years but this time has been more than four," St Cyr said.

As solar activity builds, an increase in sunspots, cooler areas on the surface caused by increased magnetic activity, leads to more eruptions known as solar flares that blast highly-charged particles of energy into the universe.

Usually, the Earth's magnetic field protects the planet from the constant stream of energised particles coming from the sun, and "even does a pretty good job defending against some storms," said Bruce Tsurutani, another of the space agency's leading astrophysicists.

But a "perfect storm" of a large hyper-charged ball of plasma and energy on a course to Earth at the speed of light could overwhelm the planet's defences and cause an unprecedented global economic disaster, according to a Nasa-funded study by the Washington-based National Academy of Sciences.

The report concludes that the cost to the United States alone could reach $2 trillion in the first year after a strike.

"It's not just a US problem, it's a global problem," St Cyr said. "Northern Europe, with its own reliance on satellite technology, will be keenly aware of the possible consequences."

Dr Richard Fisher, Nasa's chief heliophysicist, said: "We're on the threshold of a new era in which space weather can be as influential in our daily lives as ordinary terrestrial weather."

FIRES AND ELECTRIC SHOCKS

THE biggest solar storm on record, in September 1859, was so powerful that it short-circuited telegraph wires across the US and Europe, shocking operators and causing fires. The Northern Lights, the solar light show shaped by the Earth's magnetic field and usually seen only close to the North Pole, were visible in Rome.

In March 1989, a geomagnetic storm hit Canada, knocking Quebec's entire power system offline and causing damage estimated at hundreds of millions of dollars. More recently, a 1994 storm caused communications satellites to malfunction and disrupted television and radio broadcasts.

Experts believe that the cost to the United States of another damaging solar storm could reach $2 trillion in the first year after a strike, or more than 20 times the financial impact of Hurricane Katrina in 2005.