pericynthion

English

Etymology

From peri- + Cynthia (“Artemis, the Moon”) + -ion, from Ancient Greek περι- (peri-) + Κυνθία (Kunthía, “Artemis”). Compare perihelion, periastron.

Noun

pericynthion (plural pericynthions)

1. The point in an elliptical orbit around the moon that passes closest to the moon.

   Synonyms: periapsis, perilune, periselene

   • 1963, Lunar Flight Handbook - Part 1, page 117:

     Trajectory sensitivities are determined for ü=3hr and the first adjustment method is used to calculate that a midcourse correction AV_ = 7.3m/sec is required to correct to the nominal pericynthion point and time.

   • 1964, G. Kimball Miller, Jr., A simplified guidance scheme for aborting lunar landings:

     The nominal landing trajectory used in this study consists of applying constant thrust at the pericynthion of the synchronous orbit and performing a gravity-turn descent to a point about 5,500 feet above the lunar surface.

   • 2014, Victor Szebehely, Celestial Mechanics and Astrodynamics, →ISBN, page 491:

     Because of the "requirement" that the pericynthion of this type of trajectory lie on the earth-moon axis, the pericynthion loci of realistic panes pass through or very close to the earth-moon axis regardless of i_VTL.

   • 2015, Zhigang Fang, Energy Science and Applied Technology, →ISBN:

     The pericynthion's distance of 15 km and the apocynthion's distance of 100 km are known.

Related terms

• See periapsis