Nasa monitoring a strange anomaly growing in Earth's magnetic field

Nasa is monitoring a region of magnetic intensity in Earth's field between South America and southwest Africa.

The odd phenomenon, called the South Atlantic Anomaly (SAA), is known as a "dent" in Earth's magnetic field and has concerned scientists for years

While it doesn't affect Earth, orbital spacecraft including the International Space Station can pass directly through the anomaly.

When they do, the reduced magnetic field strength inside the anomaly means technological systems onboard satellites can short-circuit and malfunction if they become struck by high-energy protons emanating from the Sun.

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Sometimes there are only low-level glitches, but there is a risk of significant data loss or even permanent damage to key components which means satellite operators routinely shut down spacecraft systems before spacecraft enter the anomaly zone.

"The magnetic field is actually a superposition of fields from many current sources," geophysicist Terry Sabaka from Nasa's Goddard Space Flight Centre in Greenbelt, Maryland explained in 2020.

Scientists are forever finding out new information about the SAA. A 2016 study revealed the SAA is drifting slowly in a north-westerly direction. In 2020, it also appeared to be splitting in two.

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