= Apsides:  periapse and apoapse =

General orbits are ellipses, with the central body orbited at one focus of the ellipse.  The orbital ellipse is nearest to the central body at periapse, and farthest 180 degrees around the orbit at apoapse.

If the central body is the Earth, periapse is called perigee, and apoapse is called apogee.  For [[ https://en.wikipedia.org/wiki/Apsis | other bodies ]]:

|| Central body       || peri = near  || apo = far   ||
|| general            || periapse     || apoapse     ||
|| Earth              || perigee      || apogee      ||
|| Moon (as "Luna")   || perilune     || apolune     ||
|| Moon (as "Selene") || periselene   || aposelene   ||
|| Moon (as "??????") || pericynthion || apocynthion ||
|| Sun (as "Helios")  || perihelion   || aphelion    ||
|| Star ( as "astra") || periastron   || apastron    ||