Cosmic ray
Cosmic ray is a high-energy particle originating from astrophysical sources and propagating through space. It consists primarily of protons and atomic nuclei, with a smaller fraction of electrons and other particles.
Cosmic rays are discussed in astrophysics, particle physics, and space science.
Status
Cosmic rays are detected using ground-based and space-based instruments. Their sources, acceleration mechanisms, and interactions with interstellar and interplanetary matter remain active areas of study.