“Politically, it started to get some purchase about three years ago,” says Andrew Richards, a severe risk analyst at National Grid, which runs the UK electricity network. “We know they are real effects but we are nowhere near there, in terms of our understanding.”

Teams of scientists in North America and Europe spend their days and nights monitoring the sun and issuing warnings to governments, power companies, satellite operators and airlines.

But exactly how much to worry is unclear because proper scientific understanding about space weather is based on incidents and work done only in the last 20 to 30 years, the blink of an eye in solar terms.

In 2003, a magnetic storm triggered malfunctions in 47 satellites and led to the complete loss of one worth $640 million, according to the British Antarctic Survey, which this year launched an EU-funded space weather forecasting service for the satellite industry.

Before that, a 1989 storm was blamed for taking out the entire power network in Quebec, Canada, within 90 seconds that left millions of people without electricity for nine hours.

But the only really big storms that provide any meaningful reference point for how bad it could be, happened long before the development of nationwide power grids, the internet and mass air travel.

In 1921, a magnetic storm was blamed for putting the New York Central Railroad out of action and disrupting telegraph and telephone networks across Europe.

But the big one is known as the Carrington event in 1859, when British astronomer Richard Carrington observed and recorded a very large solar eruption that reportedly took just 17 hours to show up in the earth’s atmosphere. The aurora borealis -- or North Lights -- were seen as far south as the Caribbean.

Local news reports carried accounts of people in the northeast United States being able to read a newspaper in the middle of the night by the light of the aurora, and miners in the Rocky Mountains waking up and preparing breakfast because they thought it was morning.

The accounts are entertaining, but with about a thousand active satellites now in orbit around the earth, including the International Space Station, the damage from solar storms could present private operators like SES Global and governments with a bill in the billions of dollars.