cosmic ray

noun

Definition of cosmic ray

: 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

Auger researchers are currently working out exactly how to differentiate them from cosmic rays. Adam Hadhazy, Discover Magazine, "Scientists Hunt for A Seeming Paradox: A Magnet With Only One Pole," 13 Nov. 2018 This reduction allows more cosmic rays to enter our solar system, and our star itself. Shannon Hall, Scientific American, "The Sun Is Spitting Out Strange Patterns of Gamma Rays—and No One Knows Why," 28 Mar. 2018 Upon entering our airspace, cosmic rays first obliterate some hapless molecule in Earth’s atmosphere. Adam Hadhazy, Discover Magazine, "Scientists Hunt for A Seeming Paradox: A Magnet With Only One Pole," 13 Nov. 2018 Scientists still can't account for all the cosmic rays that come here, especially the most energetic particles. Sophia Chen, WIRED, "What's a Blazar? A Galactic Bakery for Cosmic Rays," 12 July 2018 The two instruments picked up cosmic rays (on the higher end of the energy spectrum) that come from outside of the galaxy, as well as hydrogen and helium particles (on the lower end of the energy spectrum). Elizabeth Howell, Space.com, "Here Comes the Sun! Parker Solar Probe Instruments See 'First Light'," 25 Sep. 2018 The magical muon There is a long history of using muons to image archaeological structures, a process made easier by the fact that cosmic rays provide a steady supply of these particles. Jennifer Ouellette, Ars Technica, "Italy’s famous dome is cracking, and cosmic rays could help save it," 21 Aug. 2018 So an uptick in cosmic rays should lead to an uptick in gamma rays. Shannon Hall, Scientific American, "The Sun Is Spitting Out Strange Patterns of Gamma Rays—and No One Knows Why," 28 Mar. 2018 So, the new find pegs blazars as accelerators of at least some of the fastest-moving cosmic rays as well. Mike Wall, NBC News, "High-energy 'ghost particle' traced to distant galaxy in astronomy breakthrough," 12 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cosmic ray.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of cosmic ray

1925, in the meaning defined above

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Last Updated

18 Jan 2019

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Time Traveler for cosmic ray

The first known use of cosmic ray was in 1925

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More Definitions for cosmic ray

cosmic ray

noun

English Language Learners Definition of cosmic ray

: a stream of energy that enters the Earth's atmosphere from outer space

cosmic ray

noun

Kids Definition of cosmic ray

: a stream of very penetrating particles that enter the earth's atmosphere from outer space at high speed

More from Merriam-Webster on cosmic ray

Rhyming Dictionary: Words that rhyme with cosmic ray

Britannica.com: Encyclopedia article about cosmic ray

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