NASA is keeping a close eye on a concerning anomaly that's causing problems in space. Known as the South Atlantic Anomaly, the area is where Earth's inner Van Allen radiation belt is closest to the surface of the planet.
Affecting satellites and even the International Space Station, the South Atlantic Anomaly (SAA) was initially discovered in 1958 and has been monitored ever since.
Scientists have noticed the changing shape of the SAA, realizing the rift rate is similar to the rotation differential between the surface of the Earth and its core – between 0.3° and 0.5° per year.
The region is known for giving a weakened magnetic field over South America, which allows cosmic radiation to penetrate into the atmosphere. It's important for scientists to monitor the SAA and look at how it could change in the future.
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As reported by Sustainability Times, the SAA has led to 'blazing faults' that are tearing open soil due to these unknown forces beneath the Earth's crust. It's thought that the SAA is linked to the geodynamo process in Earth’s outer core, with molten iron and nickel helping generate the planet’s magnetic field. It's formed by the Earth’s magnetic axis and a dense structure that lies 2,900 kilometers under Africa.
The tilt and the African Large Low Shear Velocity Province alter how the magnetic field is generated, resulting in a local polarity reversal and a weaker magnetic field in the SAA.
In terms of how satellites are affected, there are numerous examples of 'glitches' where high levels of energetic protons interfere with these sophisticated bits of tech. Single event upsets (SEUs) are common, with data corruption and even permanent damage to systems. Although the ISS's shielding protects astronauts, it's been known to experience problems due to the SAA.
There's even the Ionospheric Connection Explorer (ICON) that observes the SAA and closely advises other missions on how to deal with it.
Speaking in 2020, NASA Goddard geophysicist and mathematician Weijia Kuang said: "The observed SAA can be also interpreted as a consequence of weakening dominance of the dipole field in the region.
"More specifically, a localized field with reversed polarity grows strongly in the SAA region, thus making the field intensity very weak, weaker than that of the surrounding regions."
Importantly, the European Space Agency's Swarm constellation and data from NASA’s SAMPEX mission highlight an alarming change in the SAA moving northwest. As well as increasing in size, it's split into two massive lobes that are creating two centers that have minimum magnetic intensity.
This means there are more danger zones for spacecraft, with the potential for further anomalies to form if it keeps splitting.
The International Geomagnetic Reference Field (IGRF) tracks changes to Earth’s magnetic field, proving crucial for planning missions to space and general information about what's going on inside the Earth.
Even though the SAA might seem unique, records suggest that other anomalies have appeared over the eons. It's also not necessarily an early indicator of pole reversal, that's a rare event that can take place over hundreds of thousands of years.
Keeping track of the SAA is crucial for the future of space travel, with scientists wise to study this 'pothole in space'.