Van Allen radiation belts

Definition

The Van Allen radiation belts are two layers of charged particles trapped by Earth's magnetic field. These belts contain protons and electrons that spiral along the magnetic field lines, creating regions of intense radiation.

5 Must Know Facts For Your Next Test

1. The inner belt primarily contains high-energy protons while the outer belt is dominated by high-energy electrons.
2. The Van Allen belts were discovered in 1958 by James Van Allen using data from the Explorer 1 and Explorer 3 missions.
3. Charged particles in the belts move in helical paths around Earth’s magnetic field lines due to the Lorentz force.
4. Geomagnetic storms can cause significant changes in the distribution and intensity of the radiation within these belts.
5. Satellites and astronauts must be shielded from the intense radiation when passing through these belts to prevent damage.

Review Questions

• What types of charged particles are found in the inner and outer Van Allen radiation belts?
• How do geomagnetic storms affect the Van Allen radiation belts?
• What role does Earth's magnetic field play in trapping particles within the Van Allen belts?

Related terms

Lorentz Force:

The force experienced by a charged particle moving through a magnetic and electric field, given by $\mathbf{F} = q(\mathbf{E} + \mathbf{v} \times \mathbf{B})$.

Magnetic Field Lines:

Imaginary lines used to represent the direction and strength of a magnetic field, which charged particles tend to follow.

Geomagnetic Storm: A temporary disturbance of Earth's magnetosphere caused by solar wind shocks, often leading to variations in the intensity of radiation within the Van Allen belts.