992 Ce Lightshow

[mrg]

* As discussed by an article from AAAS SCIENCE Online ("Mystery Glow That Lit Up The Night Sky In 992 CE Explained" by Daniel Clery, 7 December 2016), on a dark winter night of 992 CE, the northern skies lit up, one chronicler in Saxony -- modern-day Germany -- wrote that "light like the Sun shone from the North." Another from Ulster in Ireland wrote that the heavens were "blood-red". Of course they were witnessing auroras, the northern lights, which had been stimulated to a very high level by an extremely powerful solar flare, or "superflare" on the Sun, showering the Earth with high-energy particles.

 

A few years ago, researcher noticed there were spikes in the levels of the radioactive isotope carbon-14 in tree rings found all around the world at the same time. Such an enhanced level of C14 could be caused by cosmic rays hitting the upper atmosphere and converting nitrogen-14 -- a normal constituent of air -- into C14.

 

Were the anomalies due to solar flares, or from some other celestial event? Some studies hint at reports of unusual auroras shortly before the biggest C14 spikes in 774:775 CE and 993:994 CE. To investigate researchers canvassed written records around the time of the later spike and found eight aurora sightings recorded in Saxony, northern Ireland, and the Korean peninsula, between October 992 and January 993.

 

Working from the geographic reports to determine how far south the auroras were seen, the researchers concluded that the solar storm of 992:993 was stronger than any recorded since detailed monitoring began in 1957, but likely not as strong as the well-known Carrington event in 1859, which knocked out telegraph networks worldwide. While in the 990s the storm produced little more than a nice light show, if it struck today it would likely devastate our technologically dependent society, frying satellites and knocking out Earthly power grids.

 

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This from my personal notes ... no, it is not a copy of the AAAS SCIENCE article, it's well rendered down.   I'm just seeing if there's any problem posting it.  Any complaints, let me know -- MrG (Greg Goebel)

Edited May 23, 2017 by mrg

[exchemist]

* As discussed by an article from AAAS SCIENCE Online ("Mystery Glow That Lit Up The Night Sky In 992 CE Explained" by Daniel Clery, 7 December 2016), on a dark winter night of 992 CE, the northern skies lit up, one chronicler in Saxony -- modern-day Germany -- wrote that "light like the Sun shone from the North." Another from Ulster in Ireland wrote that the heavens were "blood-red". Of course they were witnessing auroras, the northern lights, which had been stimulated to a very high level by an extremely powerful solar flare, or "superflare" on the Sun, showering the Earth with high-energy particles.

 

A few years ago, researcher noticed there were spikes in the levels of the radioactive isotope carbon-14 in tree rings found all around the world at the same time. Such an enhanced level of C14 could be caused by cosmic rays hitting the upper atmosphere and converting nitrogen-14 -- a normal constituent of air -- into C14.

 

Were the anomalies due to solar flares, or from some other celestial event? Some studies hint at reports of unusual auroras shortly before the biggest C14 spikes in 774:775 CE and 993:994 CE. To investigate researchers canvassed written records around the time of the later spike and found eight aurora sightings recorded in Saxony, northern Ireland, and the Korean peninsula, between October 992 and January 993.

 

Working from the geographic reports to determine how far south the auroras were seen, the researchers concluded that the solar storm of 992:993 was stronger than any recorded since detailed monitoring began in 1957, but likely not as strong as the well-known Carrington event in 1859, which knocked out telegraph networks worldwide. While in the 990s the storm produced little more than a nice light show, if it struck today it would likely devastate our technologically dependent society, frying satellites and knocking out Earthly power grids.

 

-------------------------------------------------------------------------------------------------------

 

This from my personal notes ... no, it is not a copy of the AAAS SCIENCE article, it's well rendered down.   I'm just seeing if there's any problem posting it.  Any complaints, let me know -- MrG (Greg Goebel)

This is interesting but what is it they have found that they did not know previously?

 

It seems they already knew C14 spikes in tree growth rings correlate with solar activity. There is a tantalising hint at some "celestial event" in this case, other than a solar storm, but this does not seem to be pursued. 

 

Or is the point that they think there was a solar storm in 993 of unparalleled intensity, which if repeated today etc etc. But then why mention the tree rings? 

 

Or am I trying to overinterpret this?

[mrg]

There is a tantalising hint at some "celestial event" in this case, other than a solar storm, but this does not seem to be pursued. 

 

The study demonstrated that the tree rings do indeed correlate to reports of solar activity.   An alternate source might have been a supernova, but I don't believe there are any nearby supernova remnants corresponding to that date.

 

There is some debate over just how powerful the Carrington event was, but it did generate auroral displays that could be seen from equatorial regions.