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
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Researchers were especially interested in how cosmic rays, a largely untested threat at the time, would affect living tissue.
—
Scott Travers, Forbes.com, 19 Apr. 2025
Join 5 others in the comments View Comments The most highly energetic particles in the universe, cosmic rays bombard Earth from space.
—Ashley Strickland, CNN, 12 Feb. 2025
The rare radioactive isotope produced by cosmic rays in the atmosphere, is used to date objects millions of years old, because its half-life is 1.4 million years.
—Paul Smaglik, Discover Magazine, 10 Feb. 2025
Exposure to cosmic rays alters the composition of a meteoroid, so the degree of alteration tells us how long a meteoroid has been in space after breaking off its parent body.
—Keith Cooper, Space.com, 3 Apr. 2025
See All Example Sentences for cosmic ray
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Scott Travers, Forbes.com, 19 Apr. 2025
Join 5 others in the comments View Comments The most highly energetic particles in the universe, cosmic rays bombard Earth from space.
—Ashley Strickland, CNN, 12 Feb. 2025
The rare radioactive isotope produced by cosmic rays in the atmosphere, is used to date objects millions of years old, because its half-life is 1.4 million years.
—Paul Smaglik, Discover Magazine, 10 Feb. 2025
Exposure to cosmic rays alters the composition of a meteoroid, so the degree of alteration tells us how long a meteoroid has been in space after breaking off its parent body.
—Keith Cooper, Space.com, 3 Apr. 2025
See All Example Sentences for cosmic ray
Cite this Entry
“Cosmic ray.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cosmic%20ray. Accessed 22 May. 2025.
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