Modern civilisation came within a week of being “pushed back to the Stone Age” after eruptions in the sun two years ago sent massive clouds of magnetised plasma through the Earth’s orbital path.

The burst of radiation would have been strong enough to destroy equipment such as navigation satellites and communications and trigger widespread blackouts had it hit the Earth, according to NASA.

“We would have been well and truly pushed back to the Stone Age for days,” said Alan Duffy, an astrophysicist at Swinburne University, of the most powerful solar storm detected in more than 150 years.

Daniel Baker of the University of Colorado told NASA’s Science News blog that the Earth and its inhabitants were “incredibly fortunate” the eruption happened when it did.