1) Particle from space 
Cosmic rays are immensely high-energy radiation, mainly originating outside the Solar System. They may produce showers of secondary particles that penetrate and impact the Earth`s atmosphere and sometimes even reach the surface. Composed primarily of high-energy protons and atomic nuclei, they are of mysterious origin. Data from the Fermi space t....
An extremely energetic (relativistic) charged particle.
a high-speed particle—either an atomic nucleus or an electron—that travels throughout the Milky Way Galaxy, including the solar system. Some of these ... [20 related articles]
Atomic nuclei (mostly protons) that are observed to strike the Earth's atmosphere with exceedingly high energies.
An extremely energetic (relativistic) charged particle.An extremely fast, energetic and relativistic (high speed) charged particle.
Atomic nuclei (mostly protons) that are observed to strike the Earth's atmosphere with extremely high amounts of energy.
Electromagnetic rays of extremely high frequency and energy; cosmic rays usually interact with the atoms of the atmosphere before reaching the surface of the Earth. Some cosmic rays come from outside the solar system while others are emitted from the Sun and pass through holes in the corona .
[n] - highly penetrating ionizing radiation of extraterrestrial origin
An extremely energetic (relativistic) charged particle. 
noun highly penetrating ionizing radiation of extraterrestrial origin; consisting chiefly of protons and alpha particles; collision with atmospheric particles results in rays and particles of many kinds
a radiation of high penetrating power that originates in outer space and consists partly of high-energy atomic nuclei.