perihelion
oxford
views updated Jun 27 2018per·i·he·li·on / ˌperəˈhēlyən; -ˈhēlēən/ •
n. (pl. -he·li·a / -ˈhēlyə; -ˈhēlēə/ or -he·li·ons) Astron. the point in the orbit of a planet, asteroid, or comet at which it is closest to the sun.The opposite of aphelion.
The Oxford Pocket Dictionary of Current English
perihelion
oxford
views updated May 08 2018perihelion The point in the
Earth's elliptical orbit at which the planet is closest to the
Sun. During the present epoch this occurs about the beginning of January, when the average amount of incident solar radiation is at a maximum. See also
APHELION.
A Dictionary of Earth Sciences AILSA ALLABY and MICHAEL ALLABY
perihelion
oxford
views updated May 21 2018perihelion Point in the
orbit of a planet, asteroid, comet or other body (such as a spacecraft) moving around the
Sun at which the body is nearest the Sun.
World Encyclopedia
perihelion
oxford
views updated May 17 2018perihelion XVII. Graecized form of modL.
perihēlium, f. Gr.
PERI- +
hélios SUN.
The Concise Oxford Dictionary of English Etymology T. F. HOAD
