Centuries-old drawings lead to better understanding of fan-shaped auroras

Physics researchers and literature researchers have joined together to better understand the rare natural phenomenon of white and red auroras fanning across the night sky in Japan. Armed with drawings and descriptions dating back to the 1700s, microfilm from the 1950s, and today’s spectral image data, they’ve confirmed the accuracy of the older depictions. They’ve also started to understand how the fan-shaped auroras appear, both in the sky and to the eye.
Source: EurekaAlert, https://www.eurekalert.org