Astronomy

• apoapsis

  (astronomy) the point in an orbit farthest from the body being orbited.

• periapsis

  (astronomy) the point in an orbit closest to the body being orbited.

• node

  (astronomy) a point where an orbit crosses a plane.

• equinoctial point

  (astronomy) either of the two celestial points at which the celestial equator...

• culmination

  (astronomy) a heavenly body's highest celestial point above an observer's horizon.

Sphere

• apex

  The point on the celestial sphere toward which the sun and solar system appear to be moving...

• nadir

  The point below the observer that is directly opposite the zenith on the imaginary sphere...

• zenith

  The point above the observer that is directly opposite the nadir on the imaginary sphere...

Also contains

• pole

  One of two points of intersection of the Earth's axis and the celestial sphere.

• antapex

  The point opposite in direction from the solar apex; the point the solar system is moving...

• exaltation

  The location of a planet in the zodiac at which it is believed to exert its maximum ...