Nearly three centuries ago ominous red skies hovered parts of Asia for days and days, mystifying local people who recorded what they saw, but had very little understanding of what was happening.
Now for the first time researchers think they have finally worked out what caused the apocalyptic scenario. And concluded the event actually went on for far longer than we had previously believed.
Historians have long understood that on the 16 -18 September 1770, during the Edo period, fiery skies lit up across Kyoto, Japan, for two days in an aurora of unparalleled power.
At the time local people, both on an individual level and in government, took notes and made drawings depicting the event.
A painting of the red aurora fanning out radially appears in the old Kyoto text ‘Seikai’, according to Japan’s national English-language newspaper The Mainichi.
And a diary from the Higashihakura family reads: “Half of the sky was enveloped in red clouds. A sliver of white clouds penetrated the Milky Way.”
The team of scientists, led by Hishashi Hayakawa from Osaka University, have access to hundreds of documents like this, but now have combined the information with geometric data giving them new levels of unparalleled insight.
They concluded that what happened was actually the longest geometric storm ever recorded.
Hayakawa said: “We believe that this storm is the longest ever known as inferred from the equator-ward extension of the aurora, although magnetic field data is unavailable at that time.”
NASA explains that geometric storms occur when the earth’s magnetic field is “peeled open like an onion” allowing energetic solar wind particles to stream down the field lines to hit the atmosphere over the poles.
This decrease lasts about 6 to 12 hours, after which the magnetic field gradually recovers over a period of several days.
And this type of ‘space weather’ doesn’t just affect what is going on beyond our planet, in fact storms of this nature have huge consequences for us living here on earth.
A solar storm in 1859, named the Carrington Event, which lasted two nights, caused such disruption that it is believed if it happened today, it would leave a trail of destruction costing up to £1.5tn in damage.
The Carrington Event lasted two nights, the geomagnetic storm in East Asia is now thought to have lasted nine.
“Facing such extreme and long-lasting magnetic storms, we have to expect the disturbance of communication, wide-range blackouts, radioactive exposure of aircraft, failure of GPS, and so on,” says Hayakawa.