It is an anniversary that may go largely unnoticed, but it's one that could have serious implications for you, me and indeed all of Western Civilisation. Ignore the events of September 1, 1859, at your peril.

Exactly 150 years ago tomorrow, something extraordinary was happening in the evening skies above Bristol. The sailors and dockers were looking up through the rigging of their boats at the sky.

In the streets the grocers, bakers, butchers and dressmakers were all standing outside their shops, their eyes fixed on the heavens.

They were all asking the same question. Why hasn't it gone dark?

Actually, it was a question that was hanging on the lips of people all over the country. Indeed, all over the world, as night "time" came, night itself simply didn't come.

Instead, the skies around the globe were lit up by the Northern Lights – the aurora borealis – which normally restrict themselves to the north pole, and the south pole (as the aurora Australis).

Most people didn't realise what was happening at the time, but the world was being buffeted by a solar superstorm – a massive influx of electromagnetic energy, bursting out of the sun in a gigantic malevolent flare.

Solar flares are not unusual – the splurges of gas are omitted regularly by our sun, but normally they do little more than cause the pretty swirls of light above the polar bears and penguins. But occasionally these flares develop into a solar storm – on average once every 11 years. Sometimes these storms are even bigger, and these powerful splurges are known as solar superstorms.

One of the few men who understood a little about what was happening that day in 1859, was one of Britain's top astronomers, Richard Carrington, who happened to be observing the sun earlier that week.

Using a filter, he was able to study the solar surface through his telescope, and he had been the first to see that something unusual was taking place.

He saw a bright flash of light erupt from the sun's surface and head straight towards his telescope.

The 50,000-mile-wide eddies of boiling hydrogen plasma erupted from the surface of the sun in a billion-tonne blob of crackling-charged gas, and careered through space towards Earth at speeds of up to a million miles an hour.

Just 48 hours after Carrington first saw the eruption, it struck our planet, and the effects were extraordinary.

Brilliant aurorae lit the night skies right down to the Tropics – their light being so brilliant it was possible to read a newspaper at midnight.

Telegraph operators received severe electric shocks as solar-induced currents surged through the networks. It was as though the Earth had been immersed in a bath of electricity.

Such damage as there was, was easy to repair. In 1859, the world ran mostly on steam and muscle. Human civilisation did not depend on a gargantuan super-network of electric power and communications. But it does now.

Electric power is modern society's cornerstone, the technology on which virtually all other infrastructures and services depend.

Experts warn that the most likely date for another comparable cosmic event is just three years away in 2012, a period when we're due another solar maximum – a peak of activity in the sun.

This is when a "superstorm" would most likely strike, probably around either the spring or autumn equinox, when the orientation of the Earth's magnetic field to the sun makes us particularly vulnerable.

It's a subject that has kept Professor Guy Nason occupied for the past few months. In the quiet of his office at Bristol University's department of mathematics, the expert statistician has been using data from NASA's monitoring of activity on the surface of the sun to try to come up with a way of predicting when the catastrophe might strike.

"The trouble at the moment is that among the data there is a lot of extra electromagnetic information that the physical scientists don't need – we call this activity that simply gets in the way 'noise'," he explains.

"My recent papers have been trying to come up with mathematical techniques to lessen this 'noise' in the data, which should in turn allow the scientists to develop a more accurate way of predicting when the next Carrington-scale event could strike.

"It's not a question of if it happens, it's very much a question of when it happens."

He adds: "When you see how much money has been spent on preparing for swine flu, you have to wonder if governments are really taking the potential danger of a major electromagnetic storm at all seriously.

"Our entire infrastructure is based on computers, satellites and electronic equipment these days. If they're all knocked out in one event, we would struggle to meet the task of fixing every computer on Earth. We would very quickly lose essential things like lighting, electricity supplies and most importantly fresh water supplies and waste management systems."

The food supply chain could quickly grind to a halt. Telecommunications would cease to exist. The internet would crash in a major way. Television and radio would go off the air. Petrol supplies would dry up.

In short, we could be sent back to the Dark Ages within weeks.

According to research published by New Scientist magazine last spring, it is predicted that a year after the event, Britain, most of Europe and North America would find itself in the grip of the deepest economic catastrophe in history.

By the end of 2013, 100,000 Europeans would have died of starvation. Ironically, while the Third World remained virtually unaffected by the crisis, the Western World would fall like so many great civilisations before it.

If the Western World did manage to claw its way back, some experts believe it could take two decades or more to recover.

Daniel Baker, a space weather expert at the University of Colorado, prepared a report for the US National Academy of Sciences earlier this year, and the conclusions are grim.

He warns that: "Every year, our human technology becomes more vulnerable".

A huge solar storm would cause massive power surges, amounting to billions of unwanted watts surging through the grids. Most critically, the transformers which convert the multi-thousand-volt current carried by the pylons into 240v domestic current would melt – thousands of them, in every country.

Twenty years ago a much smaller storm knocked out the power grid across much of eastern Canada, leaving nine million people without electricity.

So can anything be done to prevent an epic disaster?

Baker suggests reinforcing our infrastructures with a more robust electricity grid and new satellites to give warning of what is happening on the sun. That's where the theoretical work of Professor Nason could also make a difference.

"It's about speeding up the prediction process," he explains, "so at least the world would have a chance to brace itself for the storm."

It might also be worth stocking up on baked beans.