[per-uh-hee-lee-uh n, -heel-yuh n]
- the point in the orbit of a planet or comet at which it is nearest to the sun.
Origin of perihelion
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for perihelia
This tendency of the perihelia to crowd together in two opposite regions has been noticed by different writers.Comets and Meteors
The extremes of temperature at perihelia and aphelia to which comets are subjected did not bother him particularly.Astronomy
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.
- the point in its orbit when a planet or comet is nearest the sunCompare aphelion
C17: from New Latin perihēlium, from peri- + Greek hēlios sun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for perihelia
Online Etymology Dictionary, © 2010 Douglas Harper
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.