It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
A mysterious spike in atmospheric carbon-14 levels 12 centuries ago might be a sign the Sun is capable of producing solar storms dozens of times worse than anything we’ve ever seen, a team of physicists calculates in a paper published in Nature. Carbon-14 (14C) is created when high-energy radiation strikes the Earth’s upper atmosphere, converting nitrogen-14 into carbon-14, which eventually makes its way into plants via photosynthesis. Earlier this year, a team of Japanese physicists discovered a spike in 14C in tree rings of Japanese cedars dating from the 774-775 growing season. But they were unable to explain where that 14C might have come from because all possible explanations appeared unlikely.
But Adrian Melott, a physicist at the University of Kansas in Lawrence, who is the lead author of the new study, says the Japanese team made a miscalculation in ruling out one of these possibilities — a giant solar storm. The problem, Melott says, is that the Japanese team treated solar storms as if they shone like lightbulbs, radiating energy uniformly in all directions. But actually they produce “blobs” of energetic plasma that explode outwards unevenly. Adjusting for that, he says, reduces the size of the solar storm needed to produce the observed 14C spike from 1000 times larger than anything known, to only 10 to 20 times larger — meaning that a giant solar storm is suddenly back on the table as a reasonable explanation. Furthermore, observations by NASA’s Kepler space telescope have found that sunlike stars are capable of generating super-storms of this type every few hundred to 1,000 years. This doesn’t mean the Sun does the same, “but it suggests it’s reasonable”, Melott says.
Speaking of comments, one reader of the Nature.com announcement  of the researchers' paper noted that there was, indeed, a contemporary mention of a celestial display during the time in question. The Anglo-Saxon Chronicles  note that in 774 A.D., "This year also appeared in the heavens a red crucifix, after sunset." Another points out that the Cyclopaedia of Biblical, theological, and ecclesiastical literature, Volume 9  notes that the hidden, martyred body of the rather obscure Irish saint, Rumoldus, was discovered when "Celestial lights marked the place where it lay." Unfortunately, a scholarly 1922 paper  on that miraculous event better defines the legend as noting that said display was merely "a mysterious flame of light" that hovered over the river where Rumoldus had been dumped, alerting some fishermen. The 14C tree-ring mystery continues.