Produced by: Tarun Mishra Designed by: Manoj Kumar
Earth experiences constant bombardment by high-energy charged particles known as cosmic rays, primarily originating from powerful celestial events like supernova explosions.
Normally, Earth’s magnetosphere shields us from cosmic rays and harsh solar radiation from the sun, providing a protective barrier.
The magnetosphere is not static; it undergoes fluctuations, including occasional flips of its magnetic poles and periods of weakened intensity, leaving Earth less protected from cosmic rays.
Brief periods, known as magnetic field excursions, witness the disappearance of the usual magnetic poles, replaced by multiple magnetic poles, further weakening the magnetosphere’s protective strength.
Scientists explore the correlation between periods of low magnetosphere intensity and major upheavals in Earth’s biosphere, which encompasses all regions supporting life on the planet.
To understand past cosmic ray bombardment events, scientists analyze the abundances of isotopes, particularly cosmogenic radionuclides, which are formed when cosmic rays interact with particles in Earth’s atmosphere.
The Laschamps excursion, occurring approximately 41,000 years ago, serves as a well-studied example of a magnetic field excursion, during which Earth experienced a weakened magnetosphere.
Scientist Sanja Panovska presented findings at the European Geosciences Union (EGU) General Assembly 2024, demonstrating how the intensity of Earth’s magnetosphere during the Laschamps excursion resulted in increased cosmic ray bombardment, as indicated by higher concentrations of cosmogenic radionuclides such as beryllium-10.