South Atlantic Anomaly
20 May 2019
Our galaxy is one of the biggest miracles of nature. The scientific fraternity is amazed to see its astounding miracles in the form of different phenomena. Long ago, James Allen Van discovered two radiation belts. These radiation belts were discovered in 1958 and scientists were ecstatic to discover another miraculous phenomenon of nature.
It was later found out that when charged particles and cosmic rays from the Sun get trapped in Earth’s magnetic field, the immediate result was the formation of these radiation belts. The magnetic field also deflects greatly when these energetic particles gets trapped in the earth’s magnetic field. These radiation belts came to be known as Van Allen belts.
The Van Allen Belts extend from an altitude of about 640 to 58,000 km (400 to 36,040 mi) above the surface. Furthermore, they protect the atmosphere from destruction.
The South Atlantic Anomaly occurs where the Van Allen radiation belt comes closest to Earth’s surface.
Significance of South Atlantic Anomaly (SAA)
The South Atlantic Anomaly is of utmost importance to astronomical satellites orbiting the Earth at an altitude of several hundred kilometers. Interestingly, all the satellites and spacecraft passing through SAA have to necessarily enter the Van Allen radiation belt. As soon as satellites and spacecraft enter these belts, they are bombarded by protons.
This has a monumental impact on the operation of on-board electronic systems. This further causes premature aging of computer, detector and other spacecraft components. Moreover, the astronauts have a tough time in this region which is a cause of ‘shooting stars’.
A Weakening Magnetic Field
SAA is not just creating troubles for the satellites and astronauts. Scientists are concerned that it may be a reason of a massive shift in the magnetic poles.
In 2016, Japan sent its Hitomi X-ray observation satellite to space in order to study the mystery of black holes and supernovas. However, Japan’s ambitious mission was spoiled by SAA. SAA had a disastrous impact on this satellite which spun out of control and resultantly could not complete its mission.
Is South Atlantic Anomaly Growing Larger?
The swift growth of South Atlantic Anomaly has rung alarm bells among scientists. Scientists believe that South Atlantic Anomaly that stretches from Chile to Zimbabwe is fast growing. This may actually lead to weakening the protecting magnetic field surrounding the Earth. As a result, the Earth’s natural shield that protects harmful radiations from reaching the planet’s surface is fast losing its strength.
There are heightened concerns that the growth in SAA would make the dwellers of Earth more vulnerable to cancer causing agents. Despite apparently bleak situation, scientists are confident that the magnetic field would not swap its poles.
In a research conducted by Monika Korte, she concluded that, “Based on our observations of the past 50,000 years we conclude that the South Atlantic Anomaly cannot be interpreted as a sign for the beginning of a reversal of the poles.”