a huge and strange anomaly in the Earth’s magnetic field is being monitored by NASA. It stretches between South America and southwestern Africa, and is growing larger every day: because of it, satellites and spacecraft are more vulnerable to particles from the Sun.
The fact has been under observation by the North American aerospace agency for several years, and his name is South Atlantic anomaly.
NASA compares this event to a “dent” in the Earth’s magnetic field, or a “bump in space.” Although our planet is not particularly affected, objects in orbit are, including the International Space Station.
According to the agency, the South Atlantic Anomaly It is born from two characteristics of the core of our planet:
- The inclination of its magnetic axis.
- The flow of molten metals within its outer core.
NASA explains: “The Earth is a bit like a bar magnet, with north and south poles representing opposite magnetic polarities and invisible magnetic field lines encircling the planet between them.”
“But unlike a magnetic bar,” the agency continues, “The core’s magnetic field is not perfectly aligned across the globe, nor is it perfectly stable.”
As the movement of the nucleus changes over time, the magnetic field fluctuates. Hence the emergence of this “dent” or “bump in space.”
What is NASA doing to minimize the damage from the South Atlantic Anomaly?
“The South Atlantic Anomaly can be interpreted as a consequence of the weakening of the domain of the dipole field in the region”, says Weijia Kuang, a geophysicist and mathematician at Goddard’s Laboratory of Geodesy and Geophysics.
“More specifically, a localized field with reversed polarity grows strong in the region, which makes the field strength very weak, weaker than that of the surrounding regions.”
When the satellites pass through the area, operators often turn off non-essential components, in order not to be greatly affected by particles from the Sun. In the case of the International Space Station, the protection is complete, keeping the astronauts safe.
However, Instruments such as the GEDI, Global Ecosystem Dynamics Research satellite, are affected, causing intermittent signals.
This is how NASA lives “dancing” to the South Atlantic anomaly.