The Great Aurora of September 1770

What happened

A nine-night sequence of extraordinary low-latitude auroral displays recorded across Japan, China, and Korea beginning September 17, 1770. A 2017 reconstruction by Hayakawa and colleagues in The Astrophysical Journal, drawing on surviving Japanese pictorial diaries and Chinese court records, estimated the auroral oval reached magnetic latitudes below 20°, making it comparable to — and possibly exceeding in areal extent — the 1859 Carrington Event.