agencies
Thursday, March 23, 2023 11:00 PM
NASA is actively monitoring a strange anomaly in Earth’s magnetic field, a giant region of low magnetic density in the sky above the planet, stretching between South America and southwest Africa.
This broad and growing phenomenon, called the South Atlantic Anomaly, has intrigued scientists for years, perhaps none more so on the part of NASA researchers, and the space agency’s satellites and spacecraft are particularly vulnerable to the weak magnetic field strength within the anomaly, and the resulting exposure to charged particles from the sun, according to the report. For the RT report.
Also, the South Atlantic Anomaly (SAA) – likened by NASA to a “bending” in the Earth’s magnetic field, or a kind of “crack in space” – which, in general, does not affect life on Earth, but the same cannot be said of the Earth’s orbit. Spacecraft (including the International Space Station), which pass directly through the anomaly as they orbit the planet at low altitudes in Earth’s orbit.
During these encounters, the low magnetic field strength within the anomaly means that technological systems aboard satellites can short-circuit and malfunction if they collide with high-energy protons emitted from the sun.
These indiscriminate strikes can usually result in low-level malfunctions, but they carry the risk of causing significant data loss, or even permanent damage to key components—threats that require satellite operators to routinely shut down spacecraft systems before spacecraft enter an aberration zone.
And mitigating these risks in space is one of the reasons NASA is pursuing the SAA. The mystery of anomalies also represents a great opportunity to investigate a complex and difficult-to-understand phenomenon, and NASA’s vast resources and research groups are concerned with studying its occurrence.
“The magnetic field is actually a superposition of fields from many current sources,” geophysicist Terry Sabaka of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, explained in 2020.
The primary source is a swirling ocean of molten iron within the Earth’s outer core, thousands of kilometers underground. The movement of that mass generates electric currents that create the Earth’s magnetic field, but not necessarily uniformly, it seems.
A huge reservoir of dense rock called the African Great Low Shear Province, which lies about 2,900 kilometers (1,800 miles) below the African continent, is disturbing field generation, leading to a significant weakening.
“The observed SAA can also be interpreted as a result of the weakening of the dominance of the dipole field in the region,” said geophysicist and mathematician Weijia Kuang, at NASA in 2020. More specifically, the localized field with reversed polarity grows strongly in the SAA region, making the field strength Very weak, weaker than those in the surrounding areas.”
While many scientists still do not fully understand this anomaly and its implications, new insights are constantly shedding light on this strange phenomenon.
For example, one study led by NASA heliophysicist Ashley Greeley in 2016 revealed that the SAA is drifting slowly in a northwesterly direction.
However, he doesn’t just move. More importantly, the phenomenon appears to be in the process of splitting in two, as researchers discovered in 2020 that the SAA appeared to split into two different cells, each representing a separate center of magnetic minimum within the larger anomaly.
What this means for the future of SAA remains unknown, but in any case, there is evidence to suggest that the anomaly is not a new manifestation.
A study published in July 2020 indicated that this phenomenon is not a strange event in recent times, but rather a recurring magnetic event that may have affected Earth 11 million years ago.
If so, that might indicate that the South Atlantic Anomaly is neither a cause nor a harbinger of an inverting of the planet’s entire magnetic field, which is something that does happen, if not for hundreds of thousands of years at a time.
Obviously, huge questions remain, but with so much of this massive magnetic weirdness out there, it’s good to know that the most powerful space agency in the world is watching it as closely as it is.