A REGION of space around the Earth that was previously thought to be free of radiation actually teems with high-energy charged particles during solar storms. The news may dash scientists’ hopes of sending up ultra-cheap, lightweight satellites that don’t carry much protection against radiation.
The Earth is circled at the equator by two donut-shaped regions of radiation known as Van Allen belts, full of high-energy electrons trapped in the Earth’s magnetic field. The inner belt lies between 3000 and 6000 kilometres above the Earth, while the outer one lies between 20,000 and 25,000 kilometres. In the gap between the two…
