Apparent retrograde motion is the motion of a planetary or other body in a direction opposite to that of other bodies within its system as observed from a particular vantage point. Direct motion or prograde motion is motion in the same direction as other bodies.
While the terms direct and prograde are equivalent in this context, the former is the traditional term in astronomy. Prograde was first seen in an abstract of an astronomy-related professional article in 1963.
Read more about Apparent Retrograde Motion: Etymology, Retrograde Motion in Astrology
Famous quotes containing the words apparent and/or motion:
“The apparent rulers of the English nation are like the imposing personages of a splendid procession: it is by them the mob are influenced; it is they whom the spectators cheer. The real rulers are secreted in second-rate carriages; no one cares for them or asks after them, but they are obeyed implicitly and unconsciously by reason of the splendour of those who eclipsed and preceded them.”
—Walter Bagehot (1826–1877)
“subways, rivered under streets
and rivers . . . in the car
the overtone of motion
underground, the monotone
of motion is the sound
of other faces, also underground—”
—Hart Crane (1899–1932)