Kenny.OSNI@SYSTEM-M.PHOENIX.HONEYWELL@sri-unix.UUCP (08/25/83)
From: Kevin B. Kenny <Kenny.OSNI @ SYSTEM-M.PHOENIX.HONEYWELL>
While attempting to explain why a belt would be stable and a shell
wouldn't be (in the discussion about objects around Vega), I used the
terms "aphelion" and "perihelion" for the points in an orbit furthest
from and closest to the primary. My friend pointed out that since
"Helios" is _the_ Sun (i.e., _our_ sun), I should have rather said
"apastron" and "periastron". That means we have the following set of
terms:
Earth: apogee, perigee.
Moon (i.e., _our_ moon): apolune, perilune (a solecism favoured by NASA)
-or- apocynthion, pericynthion (correct but obscure)
-or- aposeleneion, periseleneion (hardest to spell,
but the clearest in meaning).
Sun (i.e., _our_ sun, Sol/Helios): aphelion, perihelion.
Stars in general: apastron, periastron.
I have also seen "apocythereion, pericythereion" (pronounced,
incidentally, with a hard "c") applied to Venus (correct, I suppose, but
extremely obscure).
Is there a good pair of terms to use for the apsides irrespective of the
identity of the primary?
/k**2 (Kenny.OSNI%PCO-Multics@CISL-Service-Multics)