{"id":393913,"date":"2026-04-11T22:58:15","date_gmt":"2026-04-11T22:58:15","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/393913\/"},"modified":"2026-04-11T22:58:15","modified_gmt":"2026-04-11T22:58:15","slug":"800-years-ago-ancient-japanese-astronomers-recorded-a-massive-solar-storm-and-modern-space-weather-technology-just-confirmed-it","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/393913\/","title":{"rendered":"800 Years Ago, Ancient Japanese Astronomers Recorded a Massive Solar Storm\u2014and Modern Space Weather Technology Just Confirmed It"},"content":{"rendered":"

Ancient Japanese writings<\/a> are guiding the use of modern cutting-edge technology, as researchers investigate medieval solar storms<\/a> for important clues to the safety of space flight today.<\/p>\n

While volatile solar activity may produce beautiful auroras, solar flares,<\/a> and coronal mass<\/a> ejections can also create space weather<\/a> conditions that are dangerous to our near-earth and even ground-based infrastructure.<\/p>\n

As the commercial space economy grows, keeping that infrastructure and human astronauts safe from solar storms<\/a> becomes an increasingly pressing concern. Now, a new study published in the Proceedings of the Japan Academy, Series B, aims to help by providing a long-term understanding of the phenomenon.<\/p>\n

Tracking Solar Storm Dangers<\/p>\n

Solar storms have come close to coinciding with crewed NASA missions in the past. Between the Apollo 16 and 17 moon missions, the Sun produced major solar proton events (SPE), blasting deadly radiation in the form of high-energy particles at rates approaching the speed of light. Such an event would have been catastrophic to the crew aboard these missions, and would still be today.<\/p>\n

In light of this, Okinawa Institute of Science and Technology (OIST) researchers have developed a new method to track historical solar weather events back to the medieval period, providing a broader timescale dataset on these important cosmic events. With their new technique, the OIST researchers have already conclusively identified an SPE event sometime between the winter of 1200 CE and the spring of 1201, as revealed in the new study.<\/p>\n

\u201cPrevious studies on historical SPEs have focused on rare, extremely powerful events. Our paper provides a basis for detecting sub-extreme SPEs \u2014 events that occur more frequently and are around 10-30% of the size of the most extreme cases, but still hazardous,\u201d said Professor Hiroko Miyahara from the OIST\u00a0Solar-Terrestrial Environment and Climate Unit.<\/p>\n

\u201cSub-extreme SPEs are more challenging to detect, but our method now allows us to efficiently identify them and better understand the conditions under which they are more likely to occur,\u201d he added.<\/p>\n

A New Method to Identify Ancient Solar Storms<\/p>\n

The team\u2019s new method begins by searching ancient texts for descriptions of events resembling SPEs, then by seeking evidence through carbon-14 measurements of buried asurano trees. Notably, carbon-14 compounds form when the handful of SPEs that manage to pierce the Earth\u2019s magnetic field encounter atmospheric gases. Measuring the amount of these compounds in preserved organic material provides data on the last 10,000 years of solar activity.<\/p>\n

Previous methods for studying these ancient events captured only the most extreme carbon-14 spikes, lacking the granularity to provide a complete picture of solar turbulence over time.<\/p>\n

It took the team more than a decade, but they developed an ultra-precise measurement technique capable of registering much smaller fluctuations than previously possible. These readings allow scientists to identify, for the first time, sub-extreme ancient SPE events.<\/p>\n

\u201cThe high-precision data not only allowed us to accurately date sub-extreme solar proton events, but it also lets us clearly reconstruct the solar cycles of the period,\u201d adds Miyahara. \u201cToday, the Sun\u2019s activity fluctuates over eleven-year-long cycles, but we\u2019ve found that the cycle was just seven to eight years long back then, indicating a very active Sun.\u201d<\/p>\n

\u201cThe SPE we have dated occurred at the peak of one of these cycles,\u201d he adds.<\/p>\n

\"solarFujiwara no Teika\u2019s diary, Meigetsuki, from the Edo period, references \u201cred lights in the northern sky,\u201d which the researchers likened to an aurora produced by a solar storm. Credit: National Archives of Japan
\nSolar Storms in Ancient Writing<\/p>\n

Where the ancient writing comes in is that the new method is extremely time-intensive, so the team needs to zero in on likely places to look rather than casting a wide net.<\/p>\n

Fujiwara no Teika, who lived from 1162 to 1241, was an important courtier and poet whose writing still survives. In one of his journals, the team noted the February 1204 CE description of \u201cred lights in the northern sky over Kyoto.\u201d<\/p>\n

\t\t <\/p>\n

\t\t\t
\n\t\t\t\t\"nasa\"\t\t\t<\/a>
\n\t\t
\n\t\t\t\t\t <\/p>\n

As the solar surface grows more turbulent, multiple volatile events are likely to co-occur. SPEs may not produce aurora as the diary appears to describe, yet they are likely to appear at the same time as the solar flares and coronal mass ejections that produce the colorful events.<\/p>\n

As the researchers suspected, a sample of asunaro wood from Aomori Prefecture, when analyzed with the new measurement technique, displayed a minor carbon-14 spike, suggesting a sub-extratreme SPE. Comparing tree-ring data from the region allowed the team to narrow the event\u2019s time period to between late 1200 CE and early 1201 CE.<\/p>\n

\u201cHistorical literature provides a candidate time window, and dendroclimatology enables direct intercomparison between detected SPE and reports of sunspots and auroras recorded in literature. Integrated approaches like these are necessary to accurately reconstruct past solar activity, helping us better understand the characteristics of extreme space weather,\u201d concluded lead author Professor Hiroko Miyahara<\/a>.<\/p>\n

\u201cFor example, while the SPE we found occurred near the peak of the solar cycle, some of the prolonged low-latitude aurora recorded in the literature seems to fall near the minimum of our reconstructed solar cycle,\u201d he added.<\/p>\n

\u201cThis is unexpected,\u201d Miyahara concludes, \u201cand we\u2019re excited to look further into what solar conditions could cause this.\u201d<\/p>\n

The paper, \u201cExtremely Active Sun from 1190 to 1220 in the Medieval Period: Intercomparison of Historical Records and Tree-ring Carbon-14<\/a>,\u201d appeared in Proceedings of the Japan Academy, Series B on April 10, 2026.<\/p>\n

Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.<\/p>\n","protected":false},"excerpt":{"rendered":"Ancient Japanese writings are guiding the use of modern cutting-edge technology, as researchers investigate medieval solar storms for…\n","protected":false},"author":2,"featured_media":393914,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[174412,4286,61,60,582,82,174413,20116,247],"class_list":{"0":"post-393913","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-ancient-writings","9":"tag-aurora","10":"tag-ie","11":"tag-ireland","12":"tag-japan","13":"tag-science","14":"tag-solar-particle-event","15":"tag-solar-storm","16":"tag-space"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/393913","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=393913"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/393913\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/393914"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=393913"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=393913"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=393913"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}