cosmic rays

British  

plural noun

1. Also called: cosmic radiation.  radiation consisting of particles, esp protons, of very high energy that reach the earth from outer space

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cosmic rays Cultural  

1. Elementary particles, mainly protons, that are produced by the sun and other stars and then strike the upper atmosphere of the Earth. Some of these particles are absorbed, some help form the Van Allen belt, and some reach the Earth's surface, where they form a part of the background radiation that constantly surrounds us.

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Example Sentences

New research led by scientists at Penn State and published in Physical Review Letters suggests that some of the highest-energy cosmic rays may be atomic nuclei heavier than iron.

From Science Daily • Jun. 9, 2026

The Amaterasu particle has been especially difficult to explain because its estimated arrival direction traces back to a cosmic void, a region of space with no clear source capable of producing ultrahigh-energy cosmic rays.

From Science Daily • Jun. 9, 2026

It studies low-energy charged particles such as ions, electrons, and cosmic rays that come from both our solar system and the wider galaxy.

From Science Daily • May 4, 2026

A photography student at a university has created unique works of art using cosmic rays high above the earth.

From BBC • Apr. 29, 2026

“I think the phenomena in the cosmic rays point the way to us,” he wrote.

From "Big Science" by Michael Hiltzik