In a dazzling and scientifically significant spectacle, the skies over Ladakh were lit up by a rare aurora in the early hours of May 11, as one of the most powerful solar storms in two decades struck Earth.
The phenomenon was triggered by a series of intense solar eruptions, or coronal mass ejections (CMEs), from hyperactive sunspot region AR13664. The resulting geomagnetic superstorm, rated G5—the highest category on the NOAA space weather scale—caused vibrant red auroral arcs to appear as far south as Ladakh, a region not typically known for auroral displays.
At the Indian Astronomical Observatory in Hanle, scientists and skywatchers witnessed a stable auroral red (SAR) arc spanning the sky from around 1:00 AM to dawn. The display was recorded in detail by observatory instruments and was visible to the naked eye from nearby Merak as well. “This was a once-in-a-lifetime event for observers in India,” said Dr. Dipankar Banerjee, solar physicist at the Indian Institute of Astrophysics. “We rarely get to see the ionosphere light up like this in Ladakh. It was both visually stunning and scientifically rich.”
The auroral event followed a sequence of six interacting CMEs, which erupted between May 8 and May 10, flinging charged particles toward Earth at speeds nearing 800 kilometers per second. Upon arrival, these CMEs compressed Earth’s magnetic field, inducing strong electric currents in the atmosphere and triggering auroras.
A team led by scientists from India, using satellite data and modeling techniques, later revealed that these CMEs formed a complex structure with twisted magnetic ropes, resulting in a unique double-flux-rope configuration. This unprecedented structure altered the way heat and particles were distributed across the plasma cloud.
The geomagnetic storm reached a Dst index of –412 nT, marking it as the most severe storm since the Halloween Storms of 2003. Beyond the beauty of the display, researchers are calling the event a scientific milestone. The thermal behavior of the CME plasma, observed to absorb heat and reach thermal equilibrium en route to Earth, has offered new insights into space weather forecasting.
“The findings help us better predict how solar storms evolve and impact Earth,” said Dr. Prateek Mishra, co-author of the recent study analyzing the event. “These storms can affect satellites, power grids, and aviation, so understanding them is critical.” As the Sun approaches its solar maximum in 2025, scientists warn that more such events may occur, bringing both spectacular sky shows and potential technological disruptions.