X-class solar flare triggers severe G4 geomagnetic storm and red aurora over Hanle, Ladakh

Key facts

• An X-class solar flare erupted on 18 January 2026, launching a Coronal Mass Ejection that hit Earth in about 25 hours and produced a G4-level severe geomagnetic storm.
• The storm generated an S4-level solar radiation event, the most intense since 2003, and forced astronauts on the International Space Station to shelter in shielded areas.
• Indian Astronomical Observatory’s all-sky camera at Hanle, Ladakh, inside the Hanle Dark Sky Reserve, recorded the resulting red aurora on 19 and 20 January 2026.
• ISRO’s Aditya-L1 spacecraft, stationed at the L1 Lagrange point 1.5 million km from Earth, provided early warning of the Coronal Mass Ejection.
• During the storm, Earth’s magnetosphere was compressed so much that geostationary satellites were briefly exposed to direct solar wind, risking communication, GPS and banking services.