What is the main constituent of cosmic rays?

Cosmic rays are not actually "rays" in the traditional sense — they are high-speed subatomic particles that travel through space and constantly bombard Earth's atmosphere from all directions. The main constituent of cosmic rays is high energy protons, which make up approximately 89% of all cosmic ray particles. These protons travel at nearly the speed of light, carrying enormous amounts of kinetic energy accumulated from violent cosmic events like supernova explosions, black holes, and neutron stars scattered across the universe.

• Composition: Cosmic rays consist of approximately 89% protons, 10% alpha particles (helium nuclei), and about 1% heavier nuclei and electrons
• Energy: Primary cosmic ray protons carry extraordinarily high energies — far beyond anything achievable by man-made particle accelerators on Earth
• Origin: Believed to originate from supernova remnants, active galactic nuclei, black holes, and other extremely energetic cosmic events
• Interaction: When high energy protons enter Earth's atmosphere, they collide with air molecules and produce showers of secondary particles called cosmic ray showers
• Discovery: Victor Hess discovered cosmic rays in 1912 during a balloon flight experiment, for which he was awarded the Nobel Prize in Physics in 1936