aphelion

[ uh-fee-lee-uhn, uh-feel-yuhn, ap-hee-lee-uhn ]

noun

, plural a·phe·li·a [uh, -, fee, -lee-, uh, uh, -, feel, -y, uh, ap-, hee, -lee-, uh].

1. Astronomy. the point in the orbit of a planet or a comet at which it is farthest from the sun.

aphelion

/ əˈfiː-; æpˈhiːlɪən /

noun

1. the point in its orbit when a planet or comet is at its greatest distance from the sun Compare perihelion

aphelion

/ ə-fē′lē-ən /

1. The point at which an orbiting body, such as a planet or comet, is farthest away from the Sun.
2. Compare apogee

Derived Forms

• apˈhelian, adjective

Other Words From

• a·pheli·an adjective

Word History and Origins

Origin of aphelion¹

1650–60; Hellenized form of New Latin aphēlium < Greek *aphḗlion ( diástēma ) off-sun (distance), neuter of *aphḗlios (adj.), equivalent to ap- ap- ² + hḗli ( os ) sun + -os adj. suffix. See apogee

Word History and Origins

Origin of aphelion¹

C17: from New Latin aphēlium (with pseudo-Greek ending -ion ) from ap- + Greek hēlios sun

Example Sentences

At its perihelion it travels thousands of leagues per minute; at its aphelion it does not pass over more than a few yards.

From Project Gutenberg

Suicide increases when the earth is in aphelion, and decreases when it is in perihelion.

From Project Gutenberg

When at aphelion the planets move slower, and when at perihelion they move quicker than at the mean distance.

From Project Gutenberg

When its centre is at the extremity most remote from the sun, or aphelion, it is the summer solstice for the northern hemisphere.

From Project Gutenberg

The solar tide varies between aphelion and perihelion from 1·9 to 2·1.

From Project Gutenberg