In May, researchers observed auroras that defied expectations, with citizens capturing stunning images of the phenomenon. These photographs, which show the sky painted in magenta, played a crucial role in helping scientists analyze the auroras, as the images came from various locations across Japan—including some from regions where such displays are rarely seen.
The study was prompted by a powerful solar flare that triggered a magnetic storm, sending electrically charged particles into Earth’s atmosphere. Associate Professor Ryuho Kataoka of the National Institute of Polar Research led the effort by inviting the public to share photos of the northern sky after the event. This call for citizen contributions resulted in 775 reports, allowing the team to estimate the angles at which the auroras were observed and to calculate that the phenomena reached altitudes of up to 1,000 kilometers.
Typically, auroras appear at around 600 kilometers and are seen as red in mid-latitude areas like Japan. However, the unusually intense auroras in May were not only taller but also took on a magenta shade. Scientists believe this color variation occurred because the familiar red light merged with a bright blue hue, the latter produced by collisions between sunlight and nitrogen molecular ions—a process that was enhanced by the intense energy of the auroras during that period.
Computer simulations conducted by the research team supported these observations. The models suggested that a massive influx of nitrogen molecular ions, lifted to unexpected heights by the magnetic storm, contributed to the rare blending of hues. Impressed by the invaluable contributions of everyday observers, Kataoka even acknowledged the "citizen scientists" in the official research paper published in Scientific Reports, highlighting the growing impact of public participation in scientific discovery.