Skywatch

  • April 11, 2013

    Episode 445: The Disappearing Van Allen Belt

    Download this episode

    Shownotes

    The solar system -- especially the inner part -- is bathed in charged particles from the Sun and cosmic radiation. Several planets with magnetic fields, including Earth, are somewhat protected from the particles because they become trapped high above the surface by magnetic field lines. The Van Allen belts, discovered in the 1950s, are a pair of radiation belts encircling the Earth. Surprisingly, two new NASA probes discovered a short-lived third belt.