What does perigean mean?
Perigean is an astronomical adjective meaning “relating to the point of closest approach to Earth.” A satellite, spacecraft, or other orbiting body reaches perigee when it is nearest Earth, and that portion of its orbit is described as perigean. The term is especially associated with the Moon and with artificial satellites, appearing in expressions such as “perigean distance,” “perigean altitude,” and “perigean passage.” It contrasts with apogean, which describes the point farthest from Earth. Although understandable through the familiar concepts of perigee and apogee, perigean remains a specialized term used mainly in astronomy, orbital mechanics, and space reporting.
adjectiveRelating to the point in an orbit at which a body is closest to Earth. In astronomy, perigean describes the nearest approach of the Moon, a satellite, or a spacecraft to Earth.
- Relating to or occurring at the point in an orbit where a body is closest to Earth.
"The probe passed through its perigean phase before beginning its long journey toward the outer planets."
"The Moon's perigean distance varies slightly over the course of its orbit."
"The spacecraft experienced its perigean passage shortly after launch."
Perigean is the word for the moment an orbit brings a space object as close to Earth as it will ever get.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does perigean come from?
Perigean was formed in English in the 19th century from a form related to perigee. Its roots are Greek: the prefix peri- means “around” or “near,” while the element ge means “earth.” The related noun perigee denotes the point in an orbit nearest Earth and comes through Latin and French from Greek.
How perigean is actually used
This is chiefly an astronomical term. It is normally used with orbit-related nouns such as distance, altitude, passage, and phase, and is less common in general prose than the related noun perigee.
Easily confused with perigean
A perigee is the point itself where an orbiting body is closest to Earth, whereas perigean is the adjective describing that point or the associated distance.
Perigee is the point of closest approach to Earth, while apogee is the point of greatest distance from it.