Sometime in the 13th century, a Japanese poet stared up into the night sky and witnessed a spectacle of fiery, apocalyptic-looking light that was fascinating and terrifying enough to immortalize in ink. He compared the vision to both a flaming moonrise and a burning mountain. So why should we care 700 years later?
What Fujiwara-no-Sadaie (aka Teika) saw centuries ago is now thought to be a solar storm. These almost unreal phenomena could pose a major hazard to our electricity-powered society. Auroral events appear to explode against the darkness when particles from the sun are blasted into Earth’s atmosphere and magnetosphere, exciting oxygen and nitrogen into releasing an otherworldly glow. Coronal mass ejections are bursts of solar plasma that can instigate storms intense enough to set off auroras so intense that they can blaze for days, causing major power outages and putting astronauts in peril. This is exactly why a team of Japanese scientists went back in time to search for solar storm patterns in documents that had previously been dead to us for centuries.
“Aurora sightings have been recorded in historical documents of low-latitude Japan and southern China because the aurora presents unusual and impressive appearances of the night sky,” said Ryuho Kataoka, Takaji Nakamura and colleagues in a paper recently published in the journal Space Weather. “The occurrence of aurorae in low-latitude regions is a manifestation of the great magnetic storms.”
While ancient texts have spoken to us about astronomical phenomena before, the benefits to a society that is always plugged in could be massive when considering the possible impact of magnetic storms. The Japanese team sifted through all the accounts they had accumulated in search of those that were recorded around the same time. Comparing the frequency of solar storms in these accounts to synonymous recent events, they determined that the vast majority of occurred when solar activity was at a maximum. What they were especially keeping an eye out for were writings describing the type of prolonged events that could have possibly been caused by coronal mass ejections.
What Teika witnessed speaks from beyond the grave:
On 1204/02/21, it was sunny. ... After sunset, red vapor appeared in the direction of north and north-east. The lower part of red vapor was shaped like a rising moon and colored white and bright. Its stripes extended faraway and was like smokes in fires. There were four or five of white parts and three or four of red vapors appeared. Is it neither cloud nor stands within clouds? Its light did not get darken and red light is mixed in the white light. It is nothing but a mystery. It is also very dreadful.
On 1204/02/23, it was sunny and quite windy. ... In the time when to put a fire on the lamp, red vapor appeared in the north and north-east. It was like a distant mountain burning. It was very dreadful.
Chinese records dated even earlier echo these phenomena:
On 14 Feb. 937, at night, red and white vapors appeared alternately, like a cultivated and exploited bamboo forest, from 23:00 to 3:00, muddily from north to the middle in the sky, flickering unstably went around the 28 lunar mansions and disappeared at the dawn.
These are not the only existing reports of ancient aurorae. Medieval Middle Eastern scientists’ observations from the same era have gone mostly untranslated, and it is speculated that there must be European accounts that have still not been discovered.
Unless we can raise the dead, we can never be completely sure that they were in awe of solar storms, though the Japanese scientists have confidence in these ghosts of the past. Either way, the research is still a valuable source of information about infrequently occurring phenomena that are destructive when they do strike. NASA’s account of a really extreme solar storm in 2002 saw the demise of power lines and even situations in which aircraft had to be rerouted. The more understanding we have of solar storms and how frequently the sun has outbursts, the more we can prepare ourselves against a potentially monstrous power outage.