There’s an evolving dent in Earth’s magnetic field over South America and the southern Atlantic Ocean — and NASA says it can cause “big headaches” for satellites.
The South Atlantic Anomaly (or SAA), an unusually weak spot in Earth’s magnetic field, is growing and splitting into two lobes. For Earthlings, the SAA currently creates no noticeable harm on the ground — but in space, the anomaly is like a “pothole” for satellites and spacecrafts.
“Earth’s magnetic field acts like a protective shield around the planet, repelling and trapping charged particles from the Sun,” NASA stated in a Monday news release.
“[But the SAA] allows these particles to dip closer to the surface than normal.”
The problem? According to NASA, particle radiation may interfere with onboard computers and data collection in space. If a satellite is hit by a high-energy proton, it can lead to temporary or permanent damage — triggering protective shutdowns by operators as they fly through the SAA.
Many low-Earth orbit spacecraft, like the International Space Station (ISS), also pass through the SAA. Astronauts are safe inside, but the SAA can cause occasional (in the ISS’s case, monthly) “blips,” or short losses, in data collection.
The SAA is caused by two features from Earth’s core: the flow of molten metals and tilt of the magnetic axis. NASA scientists want to study the anomaly — to better understand how the planet is changing, and help create a safer future for in-space instruments.
“Even though the SAA is slow-moving, it is going through some change in morphology, so it’s also important that we keep observing it by having continued missions,” Terry Sabaka, a geophysicist at NASA’s Goddard Space Flight Center, said in the Monday statement. “Because that’s what helps us make models and predictions.”
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