What are cosmic rays?

Cosmic rays are tiny particles that slam into the Earth's atmosphere at various levels of energy. Billions of cosmic rays are slamming into the Earth every second, most of them with a quite low energy. Although they are called 'cosmic rays', it should be noted that cosmic rays are point-like atomic particles. They are called cosmic rays because they are found everywhere in the Universe.

Astronomers believe that cosmic rays reach their high speeds because of the action of magnetic forces in space. There are two types of cosmic rays - primary and secondary. Their study provides scientists with information about the structure, operation, and history of the galaxy and of the Universe.