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.
The film, based on the original Marvel comics, is set during the 1960s in a retro-futuristic world led by the Fantastic Four, a family of astronauts-turned-superhuman from exposure to cosmic rays during a space mission. Eleanor Pringle, Fortune, 28 July 2025 Scientists are now especially interested in how these structures evolve, fragment or interact with other molecules under the influence of ultraviolet light, cosmic rays and shocks in interstellar space. Victoria Corless, Space.com, 30 June 2025 The Auger Observatory is a hybrid detector that uses two methods to find and study cosmic rays. Ashley Strickland, CNN Money, 20 June 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. Gabe Whisnant, MSNBC Newsweek, 24 June 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 4 Aug. 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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!