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

See Examples For:

cosmic rays

"This immense energy makes cosmic rays important in astronomy and astrophysics," said first and corresponding author of the study Tsunefumi Mizuno, associate professor at Hiroshima University's Hiroshima Astrophysical Science Center.

From Science Daily ● Aug. 2, 2026

"These highest-energy cosmic rays are thought to come from extreme astrophysical sources, like two neutron stars colliding or a massive star collapsing," Murase said.

From Science Daily ● Jun. 9, 2026

Additional theoretical work on cosmic explosions involving black holes and strongly magnetized neutron stars may also help reveal where ultrahigh-energy cosmic rays are born.

From Science Daily ● Jun. 9, 2026

"We are not saying that all ultrahigh-energy cosmic rays are ultraheavy nuclei. But if some of the highest-energy events are ultraheavy nuclei, that would impact how we search for their sources."

From Science Daily ● Jun. 9, 2026

Weaver warned that some might question whether it was necessary to build a new cyclotron at all, since cosmic rays carried energies equivalent to those to be expected from the new cyclotron.

From "Big Science" by Michael Hiltzik