The study by researchers out of Nagoya University in Japan shows just how intense<\/a> the storm was, and how it really rang the planet\u2019s magnetosphere like a bell. The study found that Earth\u2019s magnetosphere shrunk down to an amazing fifth of its usual size during the event, and took a full four days to recover. <\/p>\n \u201cBy modernizing the temporal and spatial evolution of electron density in the plasmasphere and ionosphere from the Arase satellite and ground GNSS-TEC observations, we found (a) rapid compression of the plasmasphere and slow recovery of the plasmasphere due to negative storm in the ionosphere during the May 2024 super geomagnetic storm.\u201d Lead researcher on the study Atsuki Shinbori (University of Nagoya) told *Universe Today*. \u201cThanks to the coordinated\u00a0ground and satellite observations, we made important scientific results.\u201d\u00a0\u00a0 <\/p>\n The Arase mission<\/a> was key to the finding. Launched on the second flight of JAXA\u2019s small Epsilon launcher on December 20th, 2016, Arase studies the Earth\u2019s Van Allen radiation belts. The study also looked at the storm\u2019s effect on the ionosphere via ground based receivers. <\/p>\n An incoming solar storm typically compresses the plasmasphere surrounding the Earth. This is the sheath of charged particles surrounding our planet. This protects us from the worst of solar and cosmic radiation. The May 2024 solar storm condensed the Earth\u2019s plasmasphere from its usual 44,000 kilometers above Earth\u2019s surface, down to just 9,600 kilometers. This is well within geosynchronous orbit. <\/p>\n \u201cThe spatial distribution of electron density in the plasmasphere controls the generation of high energetic particles (radiation belts) in the inner magnetosphere, and the low density condition is favorable for building the radiation belts,\u201d says Shinbori. \u201cBecause these particles have a negative impact on satellites, our scientific results are important for space weather science. Furthermore, the electron density variation in the ionosphere enhances the errors of satellite positioning for drone operation. Therefore, we need to predict such electron density variation during super geomagnetic storms.\u201d <\/p>\n Solar Cycle 25: More in Store?<\/p>\n \u201cBecause solar activity is very high, we will have a good opportunity to survey severe and\/or super geomagnetic storms such as Gannon storm,\u201d says Shinbori. \u201cIn this case, only the JAXA Arase satellite provides us with valuable data in the inner magnetosphere, plasmasphere, and ionosphere during super geomagnetic storms. Accumulation of such the datasets is important for us to understand what happens in these regions during super storms. Such new knowledge will lead to improvement of the scheme of space weather prediction for such severe events.\u201d\u00a0 <\/p>\n We remember seeing a definite reddish glow over central Germany on the night of May 10th. Seeing a powerful auroral storm can be a life-changing event; I\u2019d put it right up there with a total solar eclipse and a good meteor storm in terms of amazing astronomical events. <\/p>\n And Solar Cycle 25 is far from over. The Sun reminded us of this on U.S. Veteran\u2019s Day last month, pummeling our local space weather environment. And we may be in for more this week, as massive sunspot group Active Region AR4294 aims our way. <\/p>\n![\"The](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/53712351387_953eb93911_c_20251205_183921.jpg\"\/)
<\/a> The May 2024 solar storm as seen from Canada. Credit: Andrew Symes.<\/p>\n![\"An](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/topics_20170123_20251205_184102.jpg\"\/)
<\/a> An artist’s impression, of the Arase mission in space. Credit: JAXA.<\/p>\n![\"Arase](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/topics_20160930_20251205_184456.jpg\"\/)
<\/a> Arase in the clean room on Earth, prior to launch. Credit: JAXA.<\/p>\n
![\"A](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/Sunspots_20251205_184814.jpg\"\/)
<\/a> A massive sunspot emerges from around the solar limb, in the first week of December 2025. Credit: Dave Dickinson-Shot with a Dwarf Labs Dwarf3 smartscope.<\/p>\n