NASA observes a strange anomaly in the Earth’s magnetic field: a giant region with a lower magnetic intensity In the sky above the planet extending between South America and Southwest Africa.
This huge, developing phenomenon called Southern Atlantic anomalyIt has intrigued and affects scientists for years, and perhaps no more than NASA researchers.
The satellites and spacecraft of the Space Agency are particularly vulnerable to the weakened power of the magnetic field in the anomaly and the resulting exposure of charged particles from the sun.
Southern Atlantic Anomaly (SAA) – NASA likened On the “indentation” in the magnetic field of the Earth or a kind of “hole in space”-ordinary does not affect the life of the Earth, but the same cannot be said of an orbital spacecraft (including the International Space Station) that pass directly through the anomaly as they rotate around the planet of the low-earth orbit.
During these meetings, the reduced magnetic field strength inside the anomaly means that technological systems in board satellites can also be torn if they become affected by high -energy protons emitted by the sun.
These random shocks can usually only produce low-level problems, but they carry the risk of causing significant data loss or even permanent damage to key components-the mandatory satellite operators to exclude spacecraft systems regularly before the spacecraft enters the anomaly area.
The softening of these dangers in space is one of the reasons NASA track SAA; Another is that the mystery of the anomaly is a great opportunity to explore a complex and hard -to -understand phenomenon, and the widespread resources and research groups of NASA are uniquely well furnished for the study of the event.
“The magnetic field is actually a superposition of flights from many current sources,” geophysicist Terry Sabaka from the NASA Greenbelt Space Center, “explained Maryland in 2020.
The main source is considered a a Melted iron In the outer core of the earth, thousands of miles underground. The movement of this mass generates electrical currents that create the magnetic field of the Earth, but not necessarily equally, it looks.
A huge tank of dense rock called African large province with low cut speedSituated about 2,900 kilometers (1800 miles) below the African continent, it is believed to violate the generation of the field, which leads to the dramatic weakening effect – which is aided by the inclination of the magnetic axis of the planet.
“The SAA observed can also be interpreted as a consequence of the weakening of the dominance of the dipole field in the region,” said NASA Geophysist Godard and mathematician Weijia Quang in 2020.
“More substantially, a localized field with inverted polarity is increasing strongly in the SAA region, thus making the intensity of the field very weak, slighter than that of the surrounding regions.”
010 NASA South Atlantic anomaly 2
Satellite data suggesting that SAA is being divided. (Geomagnette department, DTU space)
Although there are many scientists who do not yet fully understand the anomaly and its consequences, new insights are constantly shedding light on this strange phenomenon.
For example, a study led by NASA Heliophysicist Ashley Grilly in 2016 revealed that SAA was slowly moving around, which was confirmed by subsequently tracking by Cubesats in studies published in 2021.
However, this does not move alone. Even more remarkable is that the phenomenon seems to be in the process of dividing two, with researchers in 2020 discovering that SAA seems to be divided into two different cellsEach of them is a separate center with a minimal magnetic intensity in the greater anomaly.
Just what this means to the future of SAA remains unknown, but in any case there is evidence that suggests that the anomaly is not a new appearance.
A study published in July 2020 suggests that the phenomenon is not a surprising event of recent times, but a recurring magnetic event that may have affected the land From 11 million years agoS
If so, it may signal that the southern Atlantic anomaly is not a trigger or predecessor of The magnetic field of the entire planet flowsWhich is something that actually happens, if not for hundreds of thousands of years at a time.
A more recent study, published in 2024, found that SAA also affects the Aurors observed on Earth.
Obviously, there are huge questions, but with this huge magnetic strangeness, it is good to know that the most powerful space agency in the world is watching it as close as they are.
“Although the SAA is slowly moving, it goes through some change in morphology, so it is also important to continue to watch it as we continue missions,” Sabaka said.
“Because it helps us make models and forecasts.”
A larger version of this article was published in August 2020.