A 13th-century Japanese poet, observing the red skies and writing his memoirs, did not think his words would save today’s astronauts. Researchers at the Okinawa Institute of Science and Technology (OIST) have linked historical medieval literature to current space weather through the memoir writings of Fujiwara no Teika Miegitsuki, 1204 Common Era (CE).
By cross-referencing his description of “red lights” in his memoirs with carbon-14 levels from ancient cypress trees, the researchers were able to identify a large solar particle event. This multidisciplinary achievement demonstrates how the Sun’s cycles were much shorter and more regular in the past, providing vital information to NASA for Artemis missions and future long-term deep space exploration.
A Japanese poem dating back 826 years revealed a massive solar storm
Research into the phenomenon of solar storms began with the story of a Japanese courtier and poet, Fujiwara no Teika, who recorded the appearance of “red lights” in the northern sky over Kyoto in February 1204, as reported in the study published at the Okinawa Institute of Science and Technology (OIST).
As defined by contemporary scientists, these phenomena are stable auroral red arcs (SAR) that appear as a result of intense geomagnetic activity.
To support his claim, astrophysicists examined the annual growth rings of ancient Asunaro cypress trees found at the event site and discovered an increase in radioactive carbon-14 consistent with the same time period in which the aurora appeared.
8-year solar cycles fuel extreme particle events
Through this research, scientists determined that the behavior of the Sun’s magnetic activity was noticeably different than it is today during the early 13th century.
At present, solar cycles last about 11 years; These cycles were shorter (typically lasting only 7 to 8 years) 800 years ago, as reported in the journal Space Weather and Space Climatology. The rapid cycling of sunspot activity corresponds to the occurrence of extreme solar particle events, which consist of high-energy radiation bursts.
These radiation events can peel off large portions of the atmosphere and severely impact electronic equipment.
800-year-old data is key to astronaut survival
Understanding past extreme solar particle events (ESPEs) is critical to sustaining human life in our space program. NASA and other companies use those past events to help develop computer simulations of potential radiation risks to astronauts as they travel outside Earth’s magnetic field. Astronauts will die on the moon or while traveling to Mars if they are exposed to an amount of radiation similar to what was recorded in 1204.
Therefore, the red lights of this superstorm are today’s modern radiation protection schemes.
The science of using trees to map ancient space weather
When high-energy solar particles collide with Earth’s atmosphere, fragmentation reactions produce carbon-14, which is absorbed by trees that were alive at the time of the collision. Each of these trees produces one growth ring per year, providing a complete, searchable, dated record of all the cosmic radiation absorbed by those trees nearly a thousand years after the impact. According to research published in the journal Nature Communications, this scientific technique, called the “Miyake Event,” allows scientists to determine the exact year of a solar storm long after the storm occurs, using carbon isotope analysis.
