What happens during the apparent retrograde motion of a planet?

a. The planet appears to move eastward with respect to the stars over a period of many nights.



b. The planet moves backward through the sky.



c. The planet moves backward in its orbit around the Sun.



d. The planet moves through constellations that are not part of the zodiac.



e. The planet rises in the west and sets in the east.What happens during the apparent retrograde motion of a planet?a



A planet is in retrograde when observations from earth appear to show the planet moving backward - but the planet doesn't change directions. It stays going the same orbital path. What causes the retrograde movement (Mars especially) is that Mars has a much larger orbit around the Sun. Therefore for at certain times of the year it appears to move backward as the Earth travels around the Sun faster.What happens during the apparent retrograde motion of a planet?Normal movement of the planets against the background stars is from west to east. Retrograde motion occurs on occasions when the Earth is passing by the planet in question in a manner that makes it appear to move westward, or backward, against the background stars. I do not like any of these answers, although b is perhaps the best of the marginal choices. I say this because it is not really moving backward - it just appears that way.What happens during the apparent retrograde motion of a planet?(I hope I am not doing someone's homework for them.)



Isn't it the moon which is "a" type movement? B seems to me to best describe retrograde motion, depending upon the definition of "sky" being the background of stars. Historically, when Mercury appeared to briefly move backward from its usual direction, e.g. in retrograde, many outrageous negative both human and natural events have occurred, much in excess of the law of averages. Theories, anyone? Regards, Larry.