LHCf gears up to probe birth of cosmic-ray showers

Cosmic rays are particles from outer space, typically protons, travelling at almost the speed of light. When the most energetic of these particles strike the atmosphere of our planet, they interact with atomic nuclei in the ...

42 years on, Voyager 2 charts interstellar space

A probe launched by NASA four days after Elvis died has delivered a treasure trove of data from beyond the "solar bubble" that envelops Earth and our neighbouring planets, scientists reported Monday.

A new theory to explain how the dunes on Titan formed

A trio of researchers with the University of Hawaii has developed a new theory to explain how the dunes on Saturn's largest moon, Titan, may have formed. In their paper published in the journal Science Advances, Matthew Abplanalp, ...

Pressure runs high at edge of solar system

Out at the boundary of our solar system, pressure runs high. This pressure, the force plasma, magnetic fields and particles like ions, cosmic rays and electrons exert on one another when they flow and collide, was recently ...

CERN simulating Jupiter

This test facility at CERN, the European Organization for Nuclear Research, was used to simulate the high-radiation environment surrounding Jupiter to prepare for ESA's JUICE mission to the largest planet in our Solar System.

page 1 from 23

Cosmic ray

Cosmic rays are energetic particles originating from outer space that impinge on Earth's atmosphere. Almost 90% of all the incoming cosmic ray particles are protons, almost 10% are helium nuclei (alpha particles), and slightly under 1% are heavier elements and electrons (beta minus particles). The term ray is a misnomer, as cosmic particles arrive individually, not in the form of a ray or beam of particles.

The variety of particle energies reflects the wide variety of sources. The origins of these particles range from energetic processes on the Sun all the way to as yet unknown events in the farthest reaches of the visible universe. Cosmic rays can have energies of over 1020 eV, far higher than the 1012 to 1013 eV that man-made particle accelerators can produce. (See Ultra-high-energy cosmic rays for a description of the detection of a single particle with an energy of about 50 J, the same as a well-hit tennis ball at 42 m/s [about 94 mph].) There has been interest in investigating cosmic rays of even greater energies.

This text uses material from Wikipedia, licensed under CC BY-SA