Muons are produced in interactions that occur in the high atmosphere between nuclei of gaseous molecules and primary cosmic rays, which are mostly high-energy protons.

Do muons exist naturally?

Approximately one muon hits every square centimeter of the Earth every minute at sea level. This rate of natural background radiation increases at higher elevations. Ultrasensitive detectors, including some neutrino and dark matter experiments, are placed deep underground to minimize the effect of atmospheric muons.

Are muons everywhere?

Muons are everywhere

They are made when high-energy particles called cosmic rays slam into atoms in Earth's atmosphere.