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Source: This post on Van Allen radiation belts has been created based on the article “SpaceX’s Polaris Dawn astronauts will make a daring trek into Earth’s Van Allen radiation belt”, published in SpaceX on 12th Sep 2024.
Why in news?
Recently, the Polaris Dawn mission made history by surpassing the Apollo program’s reach. For the first time since Apoll ventured beyond Earth’s usual orbit and passed through the Van Allen radiation belts.
About Van Allen radiation belts
| Aspects | Description |
| About | 1. The Van Allen radiation belts are two layers of charged particles (mainly electrons and protons) trapped by Earth’s magnetic field. It was discovered in 1958 by James Van Allen. 2. These belts are a critical part of Earth’s magnetosphere, the region around our planet controlled by its magnetic field. |
| Structure | Inner Radiation Belt: It was located about 600 to 6,000 kilometers (370 to 3,730 miles) above Earth’s surface. This belt is composed primarily of high-energy protons. It is relatively stable and is formed by cosmic rays interacting with the Earth’s atmosphere. Outer Radiation Belt: It is situated between 13,500 and 58,000 kilometers (8,400 to 36,000 miles) above Earth. This belt primarily contains energetic electrons. It is more dynamic than the inner belt and can be influenced by solar activity such as geomagnetic storms. |
| Formation | 1. The Van Allen belts are shaped and sustained by the interaction between Earth’s magnetic field and solar wind (a stream of charged particles emitted by the sun). 2. These particles get trapped in the Earth’s magnetic field, forming the radiation belts. 3. The intensity and size of the belts can fluctuate, particularly in response to solar storms and cosmic events. This can cause the belts to expand and even pose a threat to satellites and astronauts. |
| Importance | 1. The Van Allen belts play a crucial role in protecting Earth from harmful solar and cosmic radiation by trapping these high-energy particles. 2. However, they also pose risks to spacecraft and satellites that travel through or near them, as the intense radiation can damage electronic systems and increase the risk of radiation exposure to astronauts. |
Read more: Polaris Dawn Mission
UPSC Syllabus: Science and technology
