perihelion [per-uh-hee-lee-uh n, -heel-yuh n] ExamplesWord Origin noun, plural per·i·he·li·a [per-uh-hee-lee-uh, -heel-yuh] /ˌpɛr əˈhi li ə, -ˈhil yə/. Astronomy.
- the point in the orbit of a planet or comet at which it is nearest to the sun.
Compare. Origin of perihelion 1660–70; Greek peri- + hḗli(os) sun + -on neuter noun suffix, on the model of ; earlier in the New Latin form perihelium Related formsper·i·he·li·al, per·i·he·li·an, adjective Examples from the Web for perihelia Historical Examples of perihelia
This tendency of the perihelia to crowd together in two opposite regions has been noticed by different writers.
The extremes of temperature at perihelia and aphelia to which comets are subjected did not bother him particularly.
At the second, Encke’s comet and all others with perihelia within Mercury’s orbit would have shared a similar fate.
It is a remarkable fact, however, that the longitudes of their perihelia differ by almost exactly 180.
The maximum occurs between 30 and 60, where thirty-five perihelia are found in 30 of longitude.
British Dictionary definitions for perihelia perihelion noun plural -lia (-lɪə)
- the point in its orbit when a planet or comet is nearest the sunCompare
Word Origin for perihelion C17: from New Latin perihēlium, from peri- + Greek hēlios sun Word Origin and History for perihelia perihelion n.
“point at which a celestial body is nearest the Sun,” 1680s, coined in Modern Latin (perihelium) by Kepler (1596) from Latinizations of Greek peri “near” (see) + helios “sun” (see ). Subsequently re-Greeked.
perihelia in Science perihelion [pĕr′ə-hē′lē-ən]
- The point at which an orbiting object, such as a planet or a comet, is closest to the Sun. Compare aphelion perigee.