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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Airglow is a faint light emitted by Earth's upper atmosphere, produced when molecules emit energy after being excited by cosmic rays or ultraviolet solar radiation.
—
Kenna Hughes-Castleberry, Space.com, 9 Dec. 2025
Since entering interstellar space, the craft has been studying plasma waves, cosmic rays and magnetic fields in the heliosphere, the immense bubble of solar wind around the solar system.
—George Petras, USA Today, 25 Nov. 2025
If the cosmic ray bound turns out to be meaningless, r is allowed to be even lower.
—Big Think, 22 Oct. 2025
On Mars, long-term exposure to galactic cosmic rays poses another challenge.
—Kaif Shaikh, Interesting Engineering, 16 Oct. 2025
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Kenna Hughes-Castleberry, Space.com, 9 Dec. 2025
Since entering interstellar space, the craft has been studying plasma waves, cosmic rays and magnetic fields in the heliosphere, the immense bubble of solar wind around the solar system.
—George Petras, USA Today, 25 Nov. 2025
If the cosmic ray bound turns out to be meaningless, r is allowed to be even lower.
—Big Think, 22 Oct. 2025
On Mars, long-term exposure to galactic cosmic rays poses another challenge.
—Kaif Shaikh, Interesting Engineering, 16 Oct. 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 20 Dec. 2025.
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