Van Allen Radiation Belts: Facts & Findings

This is the belt with contain most of the powerful radiations and cosmic rays to prevent from entering the earth surface. Because of this rays earth is stable without any catastrophe. this belt is in the shape of giant donut. Earth's two main belts extend from an altitude of about 640 to 58,000 km (400 to 36,040 mi)

Giant donut-shaped swaths of magnetically trapped, highly energetic charged particles surround Earth. James Van Allen, a physicist at the University of Iowa, discovered these radiation belts in 1958 after the launch of Explorer 1, the first U.S. satellite. The radiation belts were eventually named after him.

Van Allen's experiment on Explorer 1, which launched Jan. 31, 1958, had a simple cosmic ray experiment consisting of a Geiger counter (a device that detects radiation) and a tape recorder. Follow-up experiments on three other missions in 1958 — Explorer 3, Explorer 4 and Pioneer 3 — established that there were two belts of radiation circling the Earth.

On the 60th anniversary of Explorer 1, NASA said that studies of the Van Allen belts are even more important today. "Our current technology is ever more susceptible to these accelerated particles because even a single hit from a particle can upset our ever smaller instruments and electronics," said David Sibeck, Van Allen Probes mission scientist at NASA's Goddard Space Flight Center in Maryland, in a 2018 statement. "As technology advances, it's actually becoming even more pressing to understand and predict our space environment."

            

Inner belt and outer belt:

                

            The outer belt[13,000 to 60,000 kilometres (8,100 to 37,300 mi) above the Earth's surface] is made up of billions of high-energy particles that originate from the Sun and become trapped in Earth’s magnetic field, an area known as the magnetosphere. It consists of high-energy (0.1–10 MeV) electron

                The inner belt [1,000 km (620 mi) to 12,000 km (7,500 mi) above the Earth]results from interactions of cosmic rays with Earth’s atmosphere.The inner belt contains high concentrations of electrons in the range of hundreds of keV and energetic protons with energies exceeding 100 MeV, trapped by the strong (relative to the outer belts) magnetic fields in the region.

            

Satellites that unwittingly or intentionally venture into the belts can be damaged by the radiation, which could have an impact on unprotected astronauts as well. Understanding the dynamics of this region is essential for protecting technological assets and planning crewed space missions.

Space missions to study the van allen belt:

 Multipoint observations are essential to understanding the belts’ dynamics.

      

         In 2016, the Japan Aerospace Exploration Agency, or JAXA, launched the satellite Arase to cooperate with the Van Allen Probes mission in studying the radiation belts.

         A new CubeSat mission, the Compact Radiation Belt Explorer or CERES, is scheduled to launch in April 2018 to work in conjunction with the Van Allen Probes, studying the interactions between plasma waves and electrons in Earth’s upper atmosphere.

Effects due to this belt:

1.    This belt donot extend upto the poles, so the radiations easily fall on the south and north pole of earth's surface.
2.     In this region between these  belts there is a very much change in radiation effects on the space crafts during its travelling.
3.      This powerful cosmic and dangerous radiation may cause most of the electronic devices to repair and damges the whole crafts.
4.       Intense solar activity also causes other disruptions of the Van Allen belts, which in turn are linked with such phenomena as auroras and magnetic storms.