perihelion

noun
peri·​he·​lion | \ ˌper-ə-ˈhēl-yən How to pronounce perihelion (audio) \
plural perihelia\ ˌper-​ə-​ˈhēl-​yə How to pronounce perihelia (audio) \

Definition of perihelion

: the point nearest to the sun in the path of an orbiting celestial body (such as a planet) — compare aphelion

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Other Words from perihelion

perihelial \ ˌper-​ə-​ˈhēl-​yəl How to pronounce perihelial (audio) \ adjective

Examples of perihelion in a Sentence

Recent Examples on the Web In December 2019, comet 2I/Borisov reached its closest point to the sun, 190 million miles away, known as perihelion. Fox News, "Unusual chemical composition found inside ‘alien comet’," 22 Apr. 2020 The star’s closest point to the black hole, known as perihelion, advances around in a circle by about a fifth of a degree — 12 arc minutes. Dennis Overbye, New York Times, "Dancing With a Black Hole," 16 Apr. 2020 In December 2019, comet 2I/Borisov reached its closest point to the sun, 190 million miles away, known as perihelion. Fox News, "Unusual chemical composition found inside ‘alien comet’," 22 Apr. 2020 In our own solar system, astronomers had long known that the planet Mercury behaves like this; its perihelion advances around the sun by the microscopic amount of 43 seconds of arc a century. Dennis Overbye, New York Times, "Dancing With a Black Hole," 16 Apr. 2020 In December 2019, comet 2I/Borisov reached its closest point to the sun, 190 million miles away, known as perihelion. Fox News, "Interstellar comet Borisov could be breaking apart, researchers believe," 24 Mar. 2020 The four new papers report what these instruments observed during the PSP’s first two perihelion passes, which occurred in November 2018 and April 2019. Mike Wall, Scientific American, "NASA’s Sun-Kissing Parker Solar Probe Lifts the Veil on Our Closest Star," 4 Dec. 2019 At its closest, a point called perihelion, Parker was just 15 million miles away from the sun’s surface, according to a NASA press release. Jennifer Leman, Popular Mechanics, "The Fastest Spacecraft Ever Zips Past the Sun for a Third Time," 4 Sep. 2019 Lescarbault’s sightings were never confirmed, and the perihelion precession of Mercury remained a puzzle for nearly six more decades. Quanta Magazine, "Troubled Times for Alternatives to Einstein’s Theory of Gravity," 30 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'perihelion.' 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 perihelion

1666, in the meaning defined above

History and Etymology for perihelion

New Latin, from peri- + Greek hēlios sun — more at solar

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Time Traveler for perihelion

Time Traveler

The first known use of perihelion was in 1666

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Statistics for perihelion

Last Updated

3 Jun 2020

Cite this Entry

“Perihelion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/perihelion. Accessed 3 Jun. 2020.

More from Merriam-Webster on perihelion

Britannica.com: Encyclopedia article about perihelion

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