altitude
analemma
annual variation
antinode
apex
aphelion
apoapsis
apogee
apparition
apsis
argument of perihelion
ascending node
aspect

barycenter
Barycentric Dynamical Time
Besselian elements
Besselian year

celestial coordinates
celestial equator
celestial mechanics
celestial pole
celestial sphere
central meridian
chaotic control
circular orbit
Clarke Belt
colure
conic sections
conjunction
contact
convergent point
co-orbital
Coriolis effect
co-rotation
culmination

day
declination
deep space
descending node
direct ascent
direct motion
dynamical time

Earth-orbit rendezvous
eccentricity
ecliptic
ecliptic coordinates
ellipse
elongation
ephemeris
epoch
equation of light
equator
equatorial coordinates
equatorial orbit
equinox
escape velocity
extragalactic reference frame

focus (orbital)
following

geostationary orbit
geosynchronous orbit
geosynchronous/geostationary transfer orbit (GTO)
GMT (Greenwich Mean Time)
graveyard orbit
gravity assist
gravity gradient
greatest elongation

halo orbit
heliacal rising
heliocentric
heliocentric coordinates
Hohmann orbit
horizon
horizontal coordinates
hour
hour angle
hyperbola
hyperbolic orbit
hyperbolic velocity

inclination
inequality
International Celestial Reference Frame

Julian date
Julian epoch

Keplerian orbit
Keplerian rotation curve
Kepler's equation
Kepler's laws of planetary motion

Lagrangian point
latitude variation
LEO (low Earth orbit)
libration
limb correction
line of nodes
Lissajous orbit
local horizon
local standard of rest
longitude at the epoch
longitude of the ascending node
longitude of perihelion
lower transit
lunar-orbit rendezvous
Lyapunov orbit

mean motion
mean motion resonance
mean place
MEO (medium Earth orbit)
meridian
Metonic cycle
Molniya-type orbit
month

nadir
neutral point
New Style date
node
noon
North Pole
nutation

obliquity
opposition
orbit
orbit decay
orbital element
orbital migration
orbital period
orbital resonance
orbital velocity

parabola
parabolic orbit
parabolic velocity
parking orbit
periapsis
perigee
perihelion
perturbation
planetocentric and planetographic coordinates
polar distance
polar orbit
pole
position angle
preceding
precession
prime meridian
proper motion

quasistationary orbit

radius vector
rectangular coordinates
regression of nodes
retrograde
revolution
right ascension

Saros
seasons
secular
secular acceleration
secular parallax
semi-major axis
sidereal time
solar apex
Sothic cycle
spherical astronomy
spherical coordinates
stationary point
statistical parallax
suborbital
subsolar point
sun-syncronous orbit
synchronous rotation
synodic
synodic period
syzygy

topocentric coordinates
trailing hemisphere
trajectory
transfer ellipse
transit
translunar
tropic
Tropic of Cancer
Tropic of Capricorn
True of Date (TOD)
true pole
two-body problem

Universal Time (UT)
upper transit

vertical circle
very high orbit (VHO)

zenith
zodiac