How a Japanese poet’s diary helps scientists reconstruct solar cycles : NPR

SCOTT SIMON, HOST:

An ancient diary is helping scientists confirm that a major solar storm hit the Earth 800 years ago – a storm that showed how dangerous the sun can be. The Japanese poet Fujiwara no Teika kept a personal diary called “Meigetsuki,” or “The Record Of The Clear Moon.” He described red lights cast across the Kyoto sky for three consecutive nights in 1204.

At night, there was a strange red vapor in the sky, the poet wrote, which stretched across the heavens and remained visible for several nights. Today those would be called aurora, which can happen during solar storms. Scientists then looked at old trees and found that around the same time, there was a sudden spike in carbon 14 in the tree rings, which can also happen during solar storms.

Using the poet’s observations and the clues from the trees, the event was confirmed. It showed how the sun can have powerful outbursts, which today can interfere with satellites, power grids and space missions. Today the poem about red lights in the sky can remind us of the fleeting nature of life – or, as Fujiwara no Teika wrote, day will dawn, and we will pass beyond the midpoint of fall. But will the setting moon be all that we lament?

(SOUNDBITE OF DANIEL LI’S “SOLAR STORM”)

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