What Would Be the Impact on Satellite Orbits If Earth's Magnetic Poles Reversed Suddenly?

by Alexandra Sendrea

This may have been an urgent discussion if there were historical records indicating it happening during a human’s lifetime. This isn’t something you wake up one morning and realise that your compass is showing magnetic north, but 180 degrees from its true position. You shake it. Nothing. This is simply because it takes anywhere between 2,000 and 10,000 years, with the last one occurring 781,000 years ago. But how do we know it is not happening right now? Is this something that might extinct mankind?

During the reversal of the magnetic poles, also known as geomagnetic reversal, the magnetic field becomes weaker and unstable, showing multiple temporary poles, before fully settling into the opposite polarity. 1Worryingly, according to BBC Sky at Night, over the past 200 years, Earth’s magnetic field has weakened by about 9%, which could indicate that another pole reversal is coming.

With a weak magnetic field, fewer high-energy particles are deflected, and more enter the atmosphere, penetrating further where the satellites orbit the Earth. We can currently see this over the South Atlantic Anomaly. With the increased exposure to cosmic rays and solar radiation, satellite operators flying over this area sometimes shut down to preserve themselves and cause as little damage to the data stored as possible; however, this still leads to data collection and communication errors. Scientists continue monitoring to better understand the Earth’s magnetic field using satellites such as those in the European Space Agency’s Swarm mission, but this still doesn’t hide the fact that it is slowly shifting and expanding.

The geodynamo effect generates a magnetic field that extends far beyond our atmosphere, forming the magnetosphere. 2 With the help of the magnetosphere shielding us from solar radiation, how can Mars, Earth, and Venus be losing their atmospheres at a similar rate as our Earth? But how can this be true? It puzzles me. Mars’ atmosphere primarily consists of carbon dioxide, which is heavier than oxygen and nitrogen, the elements in the Earth’s atmosphere. The lighter elements can reach escape velocity quicker; however, Mars is not only a smaller planet but also less dense, therefore has a weaker atmosphere pull, allowing gases to escape more readily. Moreover, the loss of Mars’ magnetosphere causes atmospheric erosion due to solar wind.

In conclusion, the potential geomagnetic reversal and its impact on satellite operations highlight the importance of monitoring Earth's magnetic field. Understanding these changes is critical for protecting our technologies and preparing for future challenges.

Bibliography:

1 “Scientists discover how a reversal of Earth's magnetic field could affect our climate - BBC Sky at Night” https://www.skyatnightmagazine.com/space-science/earth-magnetic-field-reversal-affect-climate. Accessed 20th August 2024.

2“How Vital Is a Planet's Magnetic Field? New Debate Rises – SPACE.com” https://www.space.com/11187-earth-magnetic-field-solar-wind.html Accessed 21st August 2024.