Historic accounts and artifacts, including a painting of the cosmic event, helped scientists estimate the strength of the magnetic storm that caused a red aurora above Kyoto, Japan, in September 1770. Photo by NiPR/Matsusaka city government
Oct. 3 (UPI) -- Scientists have modeled the extreme storm that triggered a vibrant red aurora atop Kyoto, Japan, in 1770. Researchers used historic accounts of the electromagnetic light show to estimate the storm's strength.
Recently, scientists at Tokyo's National Institute of Japanese Literature and National Institute for Polar Research got the opportunity to analyze an ancient painting of a red aurora that flashed across the skies of Kyoto on Sept. 17, 1770. The painting and associated commentary was included in a Japanese manuscript called Seikai, which translates as "understanding comets." Researchers also reviewed entries describing the aurora from the diary of the Higashi-Hakura family of Kyoto.
"The enthusiasm and dedication of amateur astronomers in the past provides us an exciting opportunity," Kiyomi Iwahashi of NIJL said in a news release. "The diary was written by a kokugakusha [scholar of ancient Japanese culture], and provides a sophisticated description of the red aurora, including a description of the position of the aurora relative to the Milky Way."
To recreate the geometries of the aurora, researchers recreated the positioning of the stars and Milky Way as they appeared in the night sky above Kyoto in 1770. They compared their model with the descriptions of the storms appearance in the sky. The historic first-hand accounts of the aurora helped researchers estimate the strength of the magnetic storm responsible for the light show.
In a new paper describing their efforts -- published this week in the journal Space Weather -- scientists likened the 1770 storm to a September 1859 storm triggered by the Carrington solar flare.
"The 1859 storm was the largest magnetic storm on record, in which technological effects were widely observed," said Ryuho Kataoka of NIPR. "It was lucky for us that the 1770 storm predated our reliance on electricity."
Researchers continue to investigate the dynamics of powerful magnetic storms from the past in order to prepare for the impact a modern magnetic storm could have on power grids, satellite communications and other technologies.
While magnetic storms remain a threat, scientists say storms as powerful as the ones that struck in 1770 and 1859 are less likely today.
"We are currently within a period of decreasing solar activity, which may spell the end for severe magnetic storms in the near future," Kataoka said. "However, we actually witnessed an extremely fast coronal mass ejection only several days ago [10 September 2017], which might be powerful enough to cause extreme storms. Fortunately, it just missed the Earth."
