perihelion
Americannoun
noun
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Etymology
Origin of perihelion
1660–70; < Greek peri- peri- + hḗli ( os ) sun + -on neuter noun suffix, on the model of perigee; earlier in the New Latin form perihelium
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After several Earth flybys and a carefully planned encounter with Jupiter, the spacecraft will settle into a 1.5-year orbit with a perihelion of about 1 AU and an inclination of up to 75°.
From Science Daily ● Oct. 14, 2025
Dr Balaji said opportunities to spot the comet may occur "in the days around perihelion, depending on local conditions and the comet's behaviour".
From BBC ● Jan. 13, 2025
The most surprising thing about this cycle, though, is probably when its extremes occur on the calendar: perihelion is in January every year, while aphelion is in July.
From Scientific American ● Jun. 30, 2023
Even as the Northern Hemisphere experiences winter’s chill, our planet on Wednesday will be at perihelion, the closest it gets to the sun during its elliptical orbit.
From New York Times ● Jan. 1, 2023
Bodies which revolve round the sun, in very long ovals, approaching him very nearly in their perihelion, but in their aphelion, passing to a distance immeasurably great.
From Conversations on Natural Philosophy, in which the Elements of that Science are Familiarly Explained by Jones, Thomas P.
In recent years a few have been discovered which are at times considerably within the orbit of Mars, the nearest perihelia being less than 15 million miles beyond the earth's orbit.
From The New Gresham Encyclopedia. Vol. 1 Part 2 Amiel to Atrauli by Various
This comet, therefore, which, according to Goldschmidt, passes beyond the orbit of Jupiter, is one of the few whose perihelia are beyond Mars.
From COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1 by Humboldt, Alexander von
Moreover, a large majority of comets would then have their aphelia in the direction of the sun’s motion, and therefore their perihelia in the opposite direction.
From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 7 "Columbus" to "Condottiere" by Various
Those—and they are many—who vaguely think that science is something different from common-sense, and that any book is scientific which talks about perihelia and asymptotes and cetacea, will find their vague notions here well corroborated.
From The Unseen World and Other Essays by Fiske, John
The art has also been applied to the observation of comets at distances from their perihelia so great as to prevent their visual observation.
From History of Astronomy by Forbes, George
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
