As you may have noticed in a short item sent out over the Associated Press wire recently, KU physicist Adrian Melott is spreading a theory that a huge solar flare happened some 1200 years ago — at least 10 to 20 times bigger than any solar storm scientists have known of before.

Melott, who in the past has also theorized that a gamma-ray burst caused a mass extinction on Earth about 440 million years ago, was the lead author on an article published in the journal Nature in late November that put forth the solar-storm theory.

The idea came from a discovery made earlier in 2012 by some Japanese physicists who studied some really, really old trees. Inside some Japanese cedars, they found a spike of carbon-14 in rings that correspond to around the year 775. Carbon-14 is something that results when high-energy radiation hits the Earth’s atmosphere.

Those Japanese scientists ruled out a solar storm as the cause, but Melott is making the case that they were incorrect about that. He noted that other possible explanations for the carbon-14 spike seem unlikely; for instance, a supernova explosion could have done it, but an explosion close enough would have caused a “blindingly bright” light in the sky lasting for months — not something that would have gone unnoticed.

If a solar storm happened, it apparently did go unnoticed. But if such a storm happened today, the result could be catastrophic. A solar storm in 1989 caused a nine-hour power outage in Quebec; the storm that may have happened 1200 years ago was about 60 times stronger. Throw in our increased reliance on electricity, and the results could be dire. “A lot of people could die,” Melott says in this blog entry from Nature (Melott’s actual article is available online too, but it requires a journal subscription).