At the same time, space weather experts were monitoring this cosmic tempest closely, aware that such storms can perturb satellite electronics, disrupt GPS navigation signals, and even elevate radiation levels for astronauts aboard the International Space Station.
What causes a solar radiation storm?
The Sun is not a gentle, unchanging sphere. It is a churning, magnetic dynamo. Sunspots – darker, magnetically intense patches on the solar surface – can become unstable, twist, and snap like stressed rubber bands. When this happens, the Sun can unleash enormous explosions of energy called solar flares, and massive clouds of charged particles called coronal mass ejections (CMEs).
These CMEs travel through space at millions of kilometres per hour. When they intersect Earth’s magnetic environment, they ram into it like an invisible wind, energizing particles high in the atmosphere. These energized particles cascade through the upper layers of the atmosphere, colliding with atoms and lighting them up – the aurorae we see in the night sky.
The S4 storm level reflects not only the number of charged particles but their energy and potential to affect technological systems. As NOAA’s Space Weather Prediction Center explained on social media: “An S4 severe solar radiation storm is now in progress – this is the largest solar radiation storm in over 20 years. The last time S4 levels were observed was in October, 2003.”
An astronomical light show … and real-world consequences
For many, the storm brought a sense of awe. In Idaho Falls, residents bundled into winter jackets and waited in parking lots beneath crystal clear skies. “I’ve never seen lights like this anywhere near here,” one local observer said as green and red ribbons stretched to the horizon. Radio static and unusual noises on amateur radio bands added to the strange charm of the night.
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Farther south, social media feeds lit up with photos of aurorae over places where the phenomenon is normally impossible. A group of students at a community college in Northern California spontaneously canceled their stargazing class to watch the sky instead – their textbook definitions replaced by a living, shifting display. What began as homework became wonder. These moments remind us that Earth’s connection to the Sun isn’t just theoretical; it’s visible and visceral.
Yet there were also engineering concerns. Airliners flying near the poles were re-routed to lower latitudes, to protect high-altitude passengers and crew from increased radiation. Satellite operators placed spacecraft in safe modes to avoid damaging electronics. Ground-based power grid managers monitored currents induced in long transmission lines, ready to take precautionary measures if needed.
India’s eyes on the Sun: Aditya-L1 and space weather science
This solar tempest arrives at an opportune moment for Indian space science. In September 2023, the Indian Space Research Organisation (ISRO) launched Aditya-L1, India’s first space observatory designed specifically to study the Sun. Positioned nearly 1.5 million km from Earth at the L1 Lagrange point, this spacecraft enjoys an uninterrupted, direct view of our star.
Aditya-L1 carries a suite of scientific instruments that continuously monitor the Sun’s outer atmosphere – including its magnetic fields and particle emissions – and track how disturbances propagate through space. The mission’s goals include understanding how solar flares and CMEs originate and how they evolve into space weather events that can impact Earth and technological systems.
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A recent study published by ISRO scientists, combining Aditya-L1 data with observations from other international spacecraft, analyzed a powerful solar storm that hit Earth in October 2024. The spacecraft’s instruments identified highly turbulent structures in the storm that compressed Earth’s magnetic field more than expected, briefly exposing some satellites in geostationary orbit to intense energetic particles.
This kind of insight is crucial because it helps space weather forecasters predict not just when a storm might arrive, but how strong its effects might be.
As ISRO explained: “Space weather refers to conditions in space caused by transient activity on the Sun … which can affect satellites, communication and navigation services, and power grid infrastructure on Earth.”
From the Carrington event to today
Solar storms are not new. The most famous space weather event in human history occurred in 1859, when a massive geomagnetic storm – the Carrington Event – sparked aurorae seen near the equator and caused telegraph systems to spark and fail.
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The recent 2026 storm, powerful though it was, did not come close to the Carrington Event in scale. But it underscores that we live in a dynamic solar system where events on the Sun can ripple outward and affect life and technology on Earth. It also highlights the importance of international scientific collaboration, with spacecraft like Aditya-L1, NASA missions, and other observatories working together to watch our star and help protect our shared infrastructure.
A Sun that never sleeps
The Sun follows an approximately 11-year activity cycle, and we are currently moving through the more active phase of Solar Cycle 25, marked by increasing numbers of sunspots and eruptive events. This means more solar storms – and more opportunities for both spectacular aurorae and scientific discoveries.
The storm of early 2026 will linger in memory not just for the beauty it brought to night skies, but for the way it tested technologies and reminded humanity of its place under the influence of our nearest star. It’s a powerful reminder that the Sun, though seemingly constant in our everyday lives, is a dynamic and sometimes dramatic neighbour – one that we are still learning to understand and anticipate.
Shravan Hanasoge is an astrophysicist at the Tata Institute of Fundamental Research.
