A rare red aurora appeared over Hanle in Ladakh after an X-class solar flare, the most powerful category, launched a coronal mass ejection that hit Earth's magnetosphere and caused a severe G4-level geomagnetic storm. The red glow came from excited oxygen atoms at altitudes above 300 km. Observations from India's Aditya-L1 solar mission recorded strong compression of the magnetosphere. Such storms can affect satellites, GPS, communications and power grids.