Earth is protected by an invisible magnetic shield called the magnetosphere, which guards us against the constant stream of particles from the Sun. However, even this shield can be pushed to its limits during powerful solar storms.
Recent findings from the Indian Space Research Organisation (Isro)’s Aditya-L1 mission have helped scientists solve a puzzle about why certain parts of our planet reacted strangely during two massive solar events in 2024.
WHAT HAPPENED DURING THE 2024 SOLAR EVENTS?
On May 10 and October 10, 2024, the Sun unleashed intense energy that triggered spectacular auroras across the globe.
Think of an aurora as a giant cosmic neon sign. The Sun constantly releases a stream of charged particles called the solar wind.
Occasionally, it lets out a massive burp of plasma known as a Coronal Mass Ejection.
When these particles hit Earth’s magnetic field, they are funnelled towards the poles. As they crash into gases like oxygen and nitrogen in our atmosphere, they release energy as light.
While these light shows were beautiful, they were accompanied by unusual magnetic disturbances.
To understand this, think of Earth’s magnetic shield like a balloon being squeezed. When the solar wind blows harder, or has high pressure, it squashes the balloon, making the magnetic strength increase.
When the wind dies down, or has low pressure, the balloon expands, and the magnetic strength decreases.
However, during these 2024 storms, the dawn sector, or the area of Earth’s magnetosphere just waking up to sunrise, behaved like a mirror.
When the rest of the world saw the magnetic field get stronger, the dawn side saw it get weaker.
When the rest of the world saw it weaken, the dawn side saw it get stronger.
In other words, the dawn sector witnessed the exact opposite of what was happening everywhere else.
HOW DID ADITYA-L1 SOLVE THE MYSTERY?
Researchers from the Indian Institute of Geomagnetism in Colaba and Isro used data from the ASPEX (Aditya Solar wind Particle EXperiment) instrument on board Aditya-L1 to track these changes.
By comparing space measurements with ground-based data, they discovered that the culprit was a high-altitude electric current.
Normally, intense electrical currents in space stay far away, near the North and South Poles.
But these 2024 storms were so violent that they pushed these polar currents towards the equator.
During the 2024 storms, these currents crowded into the dawn side of Earth like uninvited guests. Once they arrived, they created their own magnetic force that fought against Earth’s normal field and flipped the readings backwards.
This means that while the magnetic field should have increased, it actually decreased, and when it should have decreased, it actually increased.
The Indian spacecraft provided a front-row seat to the solar wind behaviour. When the October storm hit, Aditya-L1 recorded a sudden drop in solar wind pressure.
While most of the world saw a corresponding dip in magnetic strength, the dawn side saw an increase.
This confirmed that the Earth’s magnetic environment becomes highly unpredictable during peak solar cycles.
WHY SHOULD WE CARE ABOUT MAGNETIC DISTURBANCES?
These fluctuations are not just academic curiosities. Because we rely so much on technology, these magnetic flips are dangerous. They can scramble GPS for pilots, mess up satellite signals, and even cause power outages by overloading electricity grids.
By understanding how these auroral currents move during a crisis, scientists can better protect our modern technology. The research, published in the journal Geophysical Research Letters, marks a significant milestone for India’s first solar mission in its quest to understand the temperamental nature of our star.
