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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Beyond The Electromagnetic Spectrum Lately, however, astronomers are even searching for and detecting high-energy cosmic ray particles, neutrino particles, and gravitational radiation --- none of which are part of the electromagnetic spectrum. Bruce Dorminey, Forbes.com, 23 Apr. 2025 In a new study, researchers from the Los Alamos National Laboratory in New Mexico argue that this spark is often provided by cosmic ray showers. Thomas G. Moukawsher, Newsweek, 21 Mar. 2025 The cosmic ray subsystem shut off on Voyager 1 last week included a trio of telescopes studying and measuring cosmic rays, or the most highly energetic particles in the universe, releasing from the sun and Milky Way galaxy. Ashley Strickland, CNN, 5 Mar. 2025 Voyager 2’s magnetic field and plasma wave equipment will also continue operating for the foreseeable future, while its cosmic ray subsystem will be retired in 2026. Andrew Paul, Popular Science, 5 Mar. 2025 See All Example Sentences for cosmic ray

Word History

First Known Use

1925, in the meaning defined above

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

Cite this Entry

“Cosmic ray.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cosmic%20ray. Accessed 28 Apr. 2025.

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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