Cosmic Rays

space · particles · high-energy physics · Earth science

Cosmic speedsters. Cosmic rays are particles that travel through space at nearly the speed of light, making them some of the fastest things in the universe.

From far away. These particles come from outside our Solar System, traveling from the Milky Way galaxy, distant galaxies, and even from our own Sun.

Earth's shield. Our planet's magnetic field and a bubble of solar energy called the heliosphere protect us by deflecting most cosmic rays away into space.

Collision cascades. When cosmic rays do hit Earth's atmosphere, they crash into air molecules and create showers of secondary particles that spray down toward the ground.

Reaching the surface. Some secondary particles from these collisions manage to reach Earth's surface, though most get stopped high up in the atmosphere before making it down.