What three kinds of motion does the moon have?
One motion is the precession of the line of apsides: the ellipse of the lunar orbit slowly rotates counterclockwise, and completes a full revolution in about 8.850 years (3,233 days). The other motion is associated with the (clockwise) precession of the orbital plane itself about an axis perpendicular to the ecliptic. The points where the lunar orbit intersects the ecliptic (the nodes) precess with time, completing one revolution in about 18.6 years (6,793 days). The mean inclination of the lunar orbit to the ecliptic plane is 5.145. The rotation axis of the Moon is also not perpendicular to its orbital plane, so the lunar equator is not in the plane of its orbit, but is inclined to it by a constant value of 6.688 (this is the obliquity).
