Re: Odyssey Orbit

[David Bowman <David_Bowman@GEORGETOWNCOLLEGE.EDU>]

Regarding Larry C.'s comment:

> I think orbital mechanics is the only field which uses "peri" to
> mean "near or nearest" as in periapsis, perihelion, perigee,
> perijove and perilune.  I don't know the etymology of that, either.

Apparently peri is a Greek preposition for about, around, round
about, etc. (also for concerning, respecting or touching) it seems
that the peri -part of such terms as periapsis, etc. is not
necessarily supposed to signify near or nearestness as much as the
place where the orbit turns around.  A highly eccentric orbit turns
around the center of attraction at its periapsis since the orbit
changes from descending towards to ascending from the attractive body
as it loops around it there.

> ...  It surprises me that
> nobody has popularized a Mars-specific terminology for periapsis
> and apsoapsis like that used for the Moon and Jupiter.  Have the
> orbit geeks tired of the name game?

Mars-specific huh?  Hmm. Well, since most of the suffixes of 'peri'
and 'ap' seem to be Hellenic in etymology (not to mention the
prefixes themselves), how about 'periares' and 'apares'?  Recall that
Mars (Roman) = Ares (Greek).

David Bowman
David_Bowman@georgetowncollege.edu