A solar "superstorm" could knock out Earth's communications satellites, cause dangerous power surges in the national grid and disrupt crucial navigation aids and aircraft avionics, a major report has found.
It is inevitable that an extreme solar storm - caused by the Sun ejecting billions of tonnes of highly-energetic matter travelling at a million miles an hour - will hit the Earth at some time in the near future, but it is impossible to predict more than about 30 minutes before it actually happens, a team of engineers has warned.
Solar superstorms are estimated to occur once every 100 or 200 years, with the last one hitting the Earth in 1859.
Although none has occurred in the space age, we are far more vulnerable now than a century ago because of the ubiquity of modern electronics, they said.
"The general consensus is that a solar superstorm is inevitable, a matter not of 'if' but 'when?'," says a report into extreme space weather by a group of experts at the Royal Academy of Engineering in London.
In the past half century, there have been a number of "near misses" when an explosive "coronal mass ejection" of energetic matter from the Sun has been flung into space, narrowly bypassing the Earth.
In 1989 a relatively minor solar storm knocked out several key electrical transformers in the Canadian national grid, causing major power blackouts.
Similar solar storms significantly increased atmospheric radiation levels in 1956, 1972, 1989 and 2003, the experts found.
SOURCE: STEVE CONNOR