NASA tracks down a mysterious huge and growing anomaly in Earth’s magnetic field

NASA is actively monitoring a mysterious anomaly in Earth’s magnetic field: a giant region of lower magnetic intensity it extends between South America and southwestern Africa.

This vast evolving phenomenon, called South Atlantic anomalyha intrigued and concerned scientists for years, and perhaps none longer than NASA researchers.

Space agency satellites and spacecraft are particularly vulnerable to the strength of the magnetic field. weakened within the anomaly and the consequent exposure to charged particles from the Sun.

The South Atlantic Anomaly (SAA), likened by NASA to a “dent” in the Earth’s magnetic field, or a sort of “bump into space”, generally does not affect life on Earthbut the same cannot be said for orbiting spacecraft (including the International Space Station), which pass directly through the anomaly as they circle the planet.

During these encounters, the reduced strength of the magnetic field within the anomaly causes technological systems aboard the satellites may experience a short circuit and malfunction when hit by high-energy protons emanating from the Sun.

These random hits can usually produce only low-level failures, but carry the risk of causing significant data loss or even permanent damage to key components, threats that force satellite operators to shut down spacecraft systems on a regular basis. before the spacecraft enters the anomaly zone.

Mitigating these risks in space is one reason NASA is monitoring SAA; another is that the mystery of the anomaly represents a great opportunity for investigation a complex and difficult to understand phenomenon, and NASA’s vast resources and research teams are exceptionally well equipped to study the event.

“The magnetic field is actually an overlap of fields from many current sources,” explained geophysicist Terry Sabaka of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The main source is considered a swirling ocean of cast iron Inside 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 High Low Shear Rate Province, located about 2,900 kilometers under the African continent, disturbs the generation of the fieldresulting in a dramatic weakening effect.

“The observed SAA can also be interpreted as a consequence of the weakening of the dominance of the dipole field in the region,” said NASA Goddard geophysicist and mathematician Weijia Kuang.

“More specifically, a localized field with reversed polarity it grows strongly in the SAA region, making the field strength very weak, weaker than that of the surrounding regions.”

While there is much that scientists still don’t fully understand about the anomaly and its implicationsnew insights shed light about this strange phenomenon continuously.

For example, a study by NASA heliophysicist Ashley Greeley in 2016 revealed that the SAA sIt moves slowly in a northwesterly direction.

However, it’s not just about moving. Even more remarkable, the phenomenon appears to be in the process of splitting in two, and researchers in 2020 found that the ASA seemed to divide into two distinct cells, each of which represents a separate center of least magnetic intensity within the larger anomaly.

What does it mean for SAA’s future remains unknown, but in any case, there is evidence to suggest that the anomaly is not a new event.

A study published in July 2020 suggested that the phenomenon it is not a strange occurrence of recent timesbut a recurring magnetic event that may have hit the Earth as early as 11 million years ago.

If so, this could indicate that the South Atlantic anomaly is not a trigger or precursor to the planetary magnetic field reversal, which is something that actually happens, otherwise for hundreds of thousands of years at a time.

“Although the ASA moves slowly, eis undergoing some changes in landforms, so it’s also important that we continue to observe it through continuous missions,” concluded Sabaka.

Source: Scientific Advisory