direct (rotation)

When referring to rotation, direct axial rotation or orbital rotation is in a counterclockwise direction when viewed looking down from above the Sun's north pole, or the movement of a body from west to east on the celestial sphere. Also known as prograde, it is the normal direction of orbital and axial movement in the Solar System.



Retrograde motion is rotation or orbital motion in a clockwise direction when viewed from above the north pole of the primary (i.e., in the opposite sense to most satellites); the opposite of direct motion. The north pole is the one on the same side of the ecliptic as Earth's north pole. For example, Venus displays retrograde axial rotation and the outer four moons of Jupiter display retrograde orbital rotation.


The term is also applied to the apparent backward (i.e., westward) motion of a planet due to Earth's own motion.