The AI-powered English dictionary
plural perigees
(astronomy) The point, in an orbit about the Earth, that is closest to the Earth: the periapsis of an Earth orbiter. quotations examples
As the moon wheels around Earth every 28 days and shows us a progressively greater and then stingier slice of its sun-lightened face, the distance between the moon and Earth changes, too. At the nearest point along its egg-shaped orbit, its perigee, the moon may be 26,000 miles closer to us than it is at its far point.
2014 September 7, Natalie Angier, “The Moon comes around again ”, in The New York Times
(astronomy, more generally) The point, in an orbit about any planet, that is closest to the planet: the periapsis of any satellite. quotations examples
Conjunctions of I and II [Io and Europa] occur when they are near perigee and apogee respectively; conjunctions of II and III [Europa and Ganymede] occur when II [Europa] is near perigee.
1995, John H. Rogers, The Giant Planet Jupiter, Cambridge University Press, page 335
The resolution of the images obtained by this American probe [Messenger] will depend on its altitude [above Mercury] at any one time: about ten meters at perigee (200km altitude), but only one 1 km at apogee (15000km).
2002, Serge Brunier, Solar System Voyage, Cambridge University Press, page 36
[Nereid’s] apogee—farthest point from Neptune—is five times the distance of its perigee—its closest point.
2010, Ruth WalkerMary M. Shaffreyet al., Exploring Space: The High Frontier, Jones & Bartlett Learning, page 129
(possibly archaic outside astrology) The point, in any trajectory of an object in space, where it is closest to the Earth.