What is Earth's magnetosphere?

The answer

Earth's magnetosphere is a vast magnetic bubble extending about 65,000 km toward the Sun and stretching millions of kilometers in the opposite direction into a long tail. Generated by convection currents of molten iron in Earth's outer core, it deflects the solar wind and traps harmful charged particles. Without it, the solar wind would have stripped away Earth's atmosphere billions of years ago, much as it did on Mars. The magnetosphere also creates the Van Allen radiation belts and channels particles toward the poles, producing auroras. It is essential for the existence of life on Earth.