NASA warns of a growing 'weak spot' in Earth's magnetic field.
The scientists claim that the expanding 'dent' could allow dangerous solar radiation to approach the surface of our planet.
Known as the South Atlantic Anomaly (SAA), the area has been expanding westward and now stretches over 4.3 million square miles, covering parts of South America and Africa.
According to the US space agency, the 'dent' permits dangerous solar radiation particles to pass through Earth's magnetic field, which 'may knock out onboard computers and interfere with the data collecting of satellites that pass through it.'
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Since 2020, the SAA has increased by 7% and shifted 12 miles west, with new research showing that it’s starting to split into two separate weak zones.
As per SAA prediction models, this separation will persist in 2025, posing even more challenges for satellites and space missions.
The team believes the weakening could be linked to an upcoming pole reversal, where Earth’s north and south poles switch places.
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The last time this happened was 780,000 years ago. And while it's unlikely to erase the magnetic field entirely, it will happen over thousands of years.
The root cause lies deep within Earth’s core.
"The magnetic field is actually a superposition of fields from many current sources," stated geophysicist Terry Sabaka from NASA's Goddard Space Flight Center in Greenbelt, Maryland, in 2020.
Beneath our planet's surface, molten iron and nickel swirl around like a massive natural generator called the 'geodynamo'. The churning of these churning metals produces the electric currents that generate the magnetic field.
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However, NASA reported that this motion changes over time, which can cause shifts in Earth's magnetic axis and likely contributed to the formation of the SAA.
Elsewhere, some scientists suspect the African Large Low Shear Velocity Province (LLSVP) - a massive underground rock formation - may be linked to the SAA.
In a 2017 article for The Conversation, the researchers revealed that the African LLSVP could be affecting the way molten metals move in the outer core, further influencing the magnetic field above it.
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The geologic size of LLSVP seems to be the same size as the anomaly's area. While the SAA isn’t an immediate threat to people on the ground, its growth could cause more issues with satellite communication, spacecraft and technology in the future.
More studies are needed to understand the SAA's behaviour fully, but progress like this is giving scientists insights into how it’s evolving.