A surprising natural phenomenon painted the sky of Japan red between June 2024 and March 2025. The red auroras, observed during this period, revealed a strange atmospheric behavior that challenged the current space models.
This luminous event unfolded during episodes of moderate solar activity, but with a more intense injection of energy than estimated by space agencies.
Red auroras in Japan and their impact on solar storms
A study published by the University of Hokkaido and the Okinawa Institute of Science and Technology in the journal Space Weather and Space Climate indicated that the geomagnetic emissions reached unusual altitudes for these regions.
This phenomenon, recorded with specialized instruments and photographs from citizen scientists, showed an unprecedented change in the ionic composition of the atmosphere in the current solar cycle.
The concern of the scientists focused on the altitudes reached by the auroras. Traditionally, they form between 200 and 400 kilometers above the Earth; however, in Hokkaido, they extended between 500 and 800 kilometers. This demonstrated that the atmosphere absorbed more energy than the space models predicted.
The phenomenon became visible when the solar wind impacted oxygen atoms in the upper layers of the atmosphere, where the low density allowed for a sustained energetic release.
The geomagnetic storm of May 2024 and its effects
The peak of these observations occurred during the Mother’s Day storm, from May 10 to 11, 2024. This storm, with coronal mass ejections classified as G5, the highest category according to the National Oceanic and Atmospheric Administration, compressed the magnetosphere to five Earth radii.
This event caused auroras in Asia, Europe, and North America and led to a drop in the Dst index to -412 nanoteslas, becoming the sixth most intense geomagnetic storm since 1957.
The effects of these solar interactions prolonged in the upper atmosphere for months, causing unusual luminous events until the first quarter of 2025, according to Japanese scientists.
