The term retrograde basically means moving backwards or having a backward motion or direction. Direct motion on the whole is the movement of a planetary body in a direction comparable to that of other bodies within its arrangement. This sort of motion at times is known as the prograde motion.
The retrograde motion is a motion in the opposite direction. Even though the expressions direct and prograde have some what similar meaning, the term direct is a traditional expression in astronomy. Prograde was initially thought to be a summary of an astronomy-related professional item.
The term retrograde comes from the Latin expressions retro which means backwards, and gradus meaning, step. Nearly all the planets including the earth rotate in the direct sense, they usually rotate in a similar direction as they orbit the Sun.
The retrograde motion is a motion in the opposite direction. Even though the expressions direct and prograde have some what similar meaning, the term direct is a traditional expression in astronomy. Prograde was initially thought to be a summary of an astronomy-related professional item.
The term retrograde comes from the Latin expressions retro which means backwards, and gradus meaning, step. Nearly all the planets including the earth rotate in the direct sense, they usually rotate in a similar direction as they orbit the Sun.