The Van Allen Belts surround Earth and contain killer electrons, plasma waves and electrical currents that disrupt the electronics on satellites. They are named after James Van Allen, who led the team that discovered them in 1958, during the flight of the first American satellite. The Explorer 1 had on board a Geiger-Müller tube to detect cosmic rays; readings periodically went off the top of the counter’s scale. Follow-up missions, including that of Explorer 3, showed that the space around Earth contained electrons, protons, and energy created by interactions between Earth's magnetosphere, the solar wind, and cosmic rays arriving from beyond the solar system.
The image is an artist’s interpretation of the radiation belts (in green); they are doughnut-shaped regions that are full of high energy particles. The blue and red lines represent the north and south polarity of Earth’s magnetic field. The inner belt is composed of protons and electrons, and can reach down as low as 1,000 kilometres in altitude. The outer belt, which consists mainly of energetic electrons, can reach as high as 60,000 kilometres above Earth’s surface. Both rings go as far as 65 degrees north and south latitude.
The Radiation Belt Storm Probes (RBSP), launched by NASA August 30 2012, will fly in separate orbits across both the inner and outer Van Allen Belts. The mission started near the height of the Sun’s 11-year cycle (aka solar maximum). The activity on the sun affects the behaviour of the radiation belts; solar storms can swell the belts with particles and energy which in turn accelerate electrons and create electrical currents. The RBSP will examine these accelerated electrons (aka ‘killer electrons’) as well as the electrical and magnetic fields, particles and plasma waves. The goal is to improve the prediction of space weather.
The image is an artist’s interpretation of the radiation belts (in green); they are doughnut-shaped regions that are full of high energy particles. The blue and red lines represent the north and south polarity of Earth’s magnetic field. The inner belt is composed of protons and electrons, and can reach down as low as 1,000 kilometres in altitude. The outer belt, which consists mainly of energetic electrons, can reach as high as 60,000 kilometres above Earth’s surface. Both rings go as far as 65 degrees north and south latitude.
The Radiation Belt Storm Probes (RBSP), launched by NASA August 30 2012, will fly in separate orbits across both the inner and outer Van Allen Belts. The mission started near the height of the Sun’s 11-year cycle (aka solar maximum). The activity on the sun affects the behaviour of the radiation belts; solar storms can swell the belts with particles and energy which in turn accelerate electrons and create electrical currents. The RBSP will examine these accelerated electrons (aka ‘killer electrons’) as well as the electrical and magnetic fields, particles and plasma waves. The goal is to improve the prediction of space weather.
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