perihelion

noun

peri·​he·​lion ˌper-ə-ˈhēl-yən 

plural perihelia ˌper-ə-ˈhēl-yə 

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

perihelial

ˌper-ə-ˈhēl-yəl 

adjective

Examples of perihelion in a Sentence

Recent Examples on the Web

During previous perihelions, the spacecraft traversed a region called the Alfvén surface, where the solar wind — a stream of particles emitted by the sun — escapes into space. —Becky Ferreira, New York Times, 24 Dec. 2024

Close approaches, known as perihelions of the probe’s run around the sun, are valuable opportunities to view the sun’s ethereal corona up close. —Shi En Kim, Smithsonian Magazine, 23 Dec. 2024

In fact, Earth will reach its closest point to the sun, also known as perihelion, during winter in the Northern Hemisphere on Jan. 4, 2025, according to In the Sky.org. —Samantha Mathewson, Space.com, 21 Dec. 2024

As the comet approached its perihelion—the closest point in its orbit to the Sun—at around 7:30 a.m. —Max Hauptman, USA TODAY, 31 Oct. 2024

Word History

Etymology

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

First Known Use

1666, in the meaning defined above

Kids Definition

perihelion

noun

peri·​he·​lion ˌper-ə-ˈhēl-yən 

: the point in the path of a heavenly body (as a planet) that is nearest to the sun