Back in 2012, the Sun erupted with a powerful solar storm that just missed the Earth but was big enough to "knock modern civilization back to the 18th century," NASA said.

The extreme space weather that tore through Earth's orbit on July 23, 2012, was the most powerful in 150 years, according to a statement posted on the US space agency website Wednesday.

"If the eruption had occurred only one week earlier, Earth would have been in the line of fire," said Daniel Baker, professor of atmospheric and space physics at the University of Colorado.

It would have been twice as bad as the 1989 solar storm that knocked out power across Quebec, scientists said.

The National Academy of Sciences has said the economic impact of a storm like the one in 1859 could cost the modern economy more than two trillion dollars and cause damage that might take years to repair.

Experts say solar storms can cause widespread power blackouts, disabling everything from radio to GPS communications to water supplies -- most of which rely on electric pumps.

There is a 12 percent chance of a super solar storm the size of the Carrington event hitting Earth in the next 10 years, according to physicist Pete Riley, who published a paper in the journal Space Weather earlier this year on the topic.

http://news.yahoo.com/earth-survived-near-miss-2012-solar-storm-nasa-222404357.html