Earth’s Weakening Magnetic Field Affecting Satellites

Earth’s magnetic field is observing weakness, says European Space Agency. The weakness is causing malfunctioning in the spacecrafts and satellites passing over the affected region between South America and Africa.

Crux of the Matter

Earth’s Magnetic Field
The geomagnetic field is created by the convection currents of molten iron and nickel in the earth’s core. It protects the earth from cosmic radiation and charged particles from the Sun. Recently, scientists discovered that it is gradually weakening from Africa to South America. This change in the nature of the magnetic field is named ‘South Atlantic Anomaly’.

The new, eastern minimum of the South Atlantic Anomaly has appeared over the last decade and in recent years is thriving. The challenge now is to understand the processes in Earth’s core driving these changes.

Jurgen Matzka, German Research Centre for Geosciences

What Is South Atlantic Anomaly?
European Space Agency’s Swarm satellites observed this change. Swarm satellites identify and precisely measure the different magnetic signals that form Earth’s magnetic field. Scientists are yet to find what has caused the weakness in the magnetic field. However, some scientists think that the north pole and south pole are switching places. Last time “geomagnetic reversal” took place almost 8 lakh years ago. However, scientists say that approximately every 250,000 years such an incident takes place and in last 200 years, magnetic field has lost nearly 9% of its strength.

This weakening of the geomagnetic field does not harm anything at the surface level. But satellites and spacecraft passing through this region may experience malfunctioning due to weaker magnetic force.

  • Peter Peregrinus of Maricourt, was a 13th-century French scholar who conducted experiments on magnetism and wrote the first extant treatise describing the properties of magnets. His work is particularly noted for containing the earliest detailed discussion of freely pivoting compass needles.
  • William Gilbert was an English physician, physicist, and natural philosopher. William was the first to state explicitly that Earth is a magnet. A unit of magnetomotive force, also known as magnetic potential, was named ‘the Gilbert’ in his honor.
  • In physics, the dynamo theory proposes a mechanism by which a celestial body such as Earth or a star generates a magnetic field. The dynamo theory describes the process through which a rotating, convecting, and electrically conducting fluid can maintain a magnetic field. A dynamo is thought to be the source of the Earth’s magnetic field and the magnetic fields of Mercury and the Jovian planets.