Perigee vs Periherm - What's the difference?
perigee | periherm |
(astronomy) The point, in an orbit about the Earth, that is closest to the Earth: the periapsis of an Earth orbiter.
* '>citation
(astronomy, more generally) The point, in an orbit about any planet, that is closest to the planet: the periapsis of any satellite.
* 1995 , John H. Rogers, The Giant Planet Jupiter , Cambridge University Press, ISBN 978-0-521-41008-3,
* 2002 , Serge Brunier, Solar System Voyage , Cambridge University Press, ISBN 978-0-521-80724-1,
* 2010 , Ruth Walker and Mary M. Shaffrey et al., Exploring Space: The High Frontier , Jones & Bartlett Learning, ISBN 978-0-7637-8961-9,
(possibly, archaic, outside, astrology) The point, in any trajectory of an object in space, where it is closest to the Earth.
Perigee is a see also of periherm.
In context|astronomy|lang=en terms the difference between perigee and periherm
is that perigee is (astronomy) the point, in an orbit about the earth, that is closest to the earth: the periapsis of an earth orbiter while periherm is (astronomy) in an orbit around the planet mercury, the point that is closest to mercury.As nouns the difference between perigee and periherm
is that perigee is (astronomy) the point, in an orbit about the earth, that is closest to the earth: the periapsis of an earth orbiter while periherm is (astronomy) in an orbit around the planet mercury, the point that is closest to mercury.perigee
English
Noun
(en noun)page 335:
- 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 .
page 36:
- 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).
page 129:
- [Nereid’s] apogee—farthest point from Neptune—is five times the distance of its perigee —its closest point.