cosmic ray

noun

: a stream of atomic nuclei of extremely penetrating character that enter the earth's atmosphere from outer space at speeds approaching that of light

Examples of cosmic ray in a Sentence

Recent Examples on the Web Earth’s upper atmosphere is laced with muon rain, spawned by high-energy cosmic rays striking our planet. Rahul Rao, Popular Science, 17 Aug. 2023 The prevailing cold also preserves dust affected by cosmic rays, which are of significant interest to scientists. Sébastien Roblin, Popular Mechanics, 22 Aug. 2023 For a final point of comparison, Smith calculates that cosmic rays interacting with the Earth’s atmosphere over the Pacific Ocean annually cause the natural deposition of 2,000 times more tritium than will be introduced by the gradual Fukushima release. Chris Baraniuk, WIRED, 18 July 2023 Neutrinos are produced by interactions between high-energy particles called cosmic rays and galactic gas and dust, according to the statement. Will Sullivan, Smithsonian Magazine, 30 June 2023 These isotopes form when cosmic rays, originating far from our solar system, slam into the rocks on Earth. Paul Bierman, Fortune, 24 July 2023 The telescope would scan the pyramid with cosmic ray muons, high-energy particles that are created when cosmic rays from outer space rain down and collide with atoms in Earth’s atmosphere. NBC News, 4 May 2022 And very few places in the universe have magnetic fields strong enough to whip cosmic rays up to sufficient energies. Thomas Lewton, Quanta Magazine, 29 June 2023 That’s because neutrinos are products of cosmic rays, cryptic high-energy particles constantly streaming throughout the universe from all directions. Rahul Rao, Popular Science, 29 June 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cosmic ray.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1925, in the meaning defined above

Time Traveler
The first known use of cosmic ray was in 1925

Dictionary Entries Near cosmic ray

Cite this Entry

“Cosmic ray.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cosmic%20ray. Accessed 4 Oct. 2023.

Kids Definition

cosmic ray

noun
: a stream of atomic nuclei of extremely penetrating character that enter the earth's atmosphere from outer space at speeds approaching that of light

More from Merriam-Webster on cosmic ray

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