A $100 detector can see invisible particles raining down from space

Tiny particles from space are passing through Earth all the time, even though we cannot see, hear, feel, taste, or smell them.

Many of these particles are linked to cosmic rays, extremely energetic particles that can come from exploding stars and other violent events far beyond our solar system. When cosmic rays strike atoms high in Earth's atmosphere, they create showers of secondary particles. Among them are muons, which can travel through the atmosphere and even penetrate underground.

University of Delaware physics professor Spencer Axani has developed a device called CosmicWatch that makes it much easier to detect these otherwise invisible particles. The technology is now being used by everyone from high school students to professional researchers.

A $100 Detector for Invisible Cosmic Particles