New Delhi— India’s first solar observatory Aditya-L1 has helped scientists understand why the most powerful solar storm in over twenty years behaved in an unexpectedly intense manner when it hit Earth in May 2024, ISRO said on Tuesday. The observatory worked alongside six American satellites, including NASA’s Wind, providing highly accurate magnetic field data that allowed researchers to examine the rare space weather event from several vantage points.
According to ISRO, the May storm—now referred to as “Gannon’s storm”—was triggered by a sequence of massive coronal mass ejections (CMEs), which are giant bursts of superheated gas and magnetic energy hurled from the Sun into space. When such bursts collide with Earth, they can rattle the planet’s magnetic shield and disrupt satellites, GPS systems, communication networks and even power grids.
A team of Indian scientists has published a landmark study in Astrophysical Journal Letters, offering new insights into why this storm behaved so differently. ISRO said scientists detected an unusual phenomenon inside the storm: the Sun’s magnetic fields, shaped like twisted ropes, were snapping and reconnecting as the storm travelled through space.
Typically, a CME carries a single twisted magnetic structure that interacts with Earth’s magnetic field. But, in this case, two CMEs collided and compressed each other so forcefully that magnetic field lines inside one of them broke and reattached in new patterns—a process known as magnetic reconnection. This sudden shift intensified the storm’s impact far beyond expectations.
Satellites also picked up a sharp increase in particle speed, confirming the reconnection event. Using precise measurements from Aditya-L1, scientists were able to map the reconnection zone for the first time.
Researchers discovered that the region experiencing magnetic tearing and reconnection was enormous—around 1.3 million kilometres wide, nearly 100 times bigger than Earth. ISRO said such a massive magnetic restructuring within a CME had never been observed before.
The space agency stressed that the discovery improves scientific understanding of how solar storms evolve during their journey from the Sun to Earth. It also marks a significant milestone for India’s growing role in global space research. With Aditya-L1’s contributions, ISRO said the country is better equipped to study and predict dangerous solar storms in the future.
Launched in September 2023, Aditya-L1 is India’s first space-based mission dedicated to studying the Sun.
