Eclipitic orbit is an orbit with inclination to the plane of reference (i.d. ecliptic) equal to zero.

As the ecliptic orbits lack nodes:

• longitude of the ascending node is then usually assumed to be zero and thus ascending node is placed in the reference direction (usually vernal equinox),
• argument of periapsis is undefined.

See also

• Longitude of the ascending node
• Argument of periapsis
• Equatorial orbit