retrograde motion- earth?

Question

will the earth ever forgo a retrograde motion. was reading up that this is something that happens to other planets, recently to Mars.
also a sign of the end of the world in certain religious beliefs!!!

i am told that one of the last sign of the end of the wold in islam is that the sun will rise from the west as apposed to east! that's why i want to test this rethrograde theory and see what people think!

Answer 1

Hi Unmaitre!

It's all in your mind. Literally! (giggles)

No planet, earth included, ever actually changes direction. Planets are so massive and move so fast that they cannot be made to change direction without applying the most incredible amount of energy, such as some sort of near collision. That's not going to happen any time soon.

Retrograde motion is only an apparent effect that we notice about other planets. It comes in three forms:

1) Planets farther out than earth move more slowly in their orbits than earth does. Each year or so, in our planet's trip around the sky, we catch up with and pass them. Watching, say, Mars against the background of stars, Mars seems to slow down and then move backward for a few months. Astronomers call this Retrograde Motion. Of course Mars isn't ACTUALLY slowing down or running backward. It just looks that way. It's similar to what happens if you're sitting on a fast train and you pass a slower train. If you casually glance out the window, the slower train looks like it's moving backward.

2) Venus and Mercury orbit the sun in paths that, to us, appear never far from the sun. (Venus can never be seen at midnight, except for the rare case of high latitudes with midnight sun.) For most of their orbits, when they're alongside the sun or behind it (as seen from earth), they seem to follow the sun across the sky, moving in the same direction as the sun appears to move. When Venus reaches the part of its orbit where it's about to come in front of the sun (from our vantage point) it suddenly seems to change direction and shift from the evening sky into the morning sky. That's called Retrograde Motion too. Of course, if you were on Venus, you'd feel nothing unusual. In fact, looking up through the sky of Venus (if that were possible) at that time, you'd see earth in Retrograde Motion.

3) Most planets rotate on their axis in the same direction. Jupiter, Mars and also most moons, all spin in the same direction as earth does. Venus does not, however. On Venus, the sun would appear to rise in the west and set in the east. No one knows why. Since their day on Venus seems to run in the wrong direction, we call this Retrograde. Of course, if you were on Venus, you'd notice nothing unusual about it, and you might wonder how come all the other planets spin the wrong way!

There is absolutely no religious significance to any of this. It is all 100% predictable to millions of years into the future. Retrograde Motion of the planets is no more a guide to the "end times" than the possibility that the sun will rise in 2 1/2 hours (which I'm highly, highly confident it will!). Mercury, for instance, is in Retrograde Motion at this very moment (as seen from earth).

I know you'd like a demonstration, so here it comes! I am now going to use my mighty apocalyptic powers to change the direction of the heavens! I'm pointing my finger into the sky right now toward Mars! (Actually, it's overcast, but I know where Mars is.) Using my levitation, I'm ordering Mars to slow down its motion and move backward in the sky! I'm feeling lazy right now, so I'm only going to use a fraction of my power, so I'll only make Mars slow down gradually, until November 15th and then make it enter Retrograde Motion on November 15th!!! (GMT) Better start quaking in your boots, all you End-Timers, at my mighty apocalyptic powers!

Answer 2

Retrograde Movement

Answer 3

It's not possible unless viewing earth from another world's orbit, especially one closer to the sun.

Retrograde motion, like for Mars, is not the true motion of the planet, which is not changing - it's following a circular path at a constant speed. Mars' retrograde motion is its apparent motion in Earth's sky.

Imagine two people start moving around the center of a room who walls are painted with stars. One starts near the walls and moves slowly, and one starts nearer to the middle and moves more quickly. They start off moving in the same direction - to the left counterclockwise).

Of course, the one in the closer orbit will reach the left side of his circular path first, and it will start moving him to the right as the guy near the wall is still going left. From someone at a position upon the inner planet/person's surface looking up/out at the far person against the stars of the wall, the far person's position will appear to scoot forward, then slow and maybe even reverse, then scoot forward again as the view from the inner orbit changes. Mars only appears to do that. Its motion is not really changing.

Earth could appear to do this when viewing from Venus or Mercury.

It's not likely that anything, even super future tech, could ever reverse the actual direction of the Earth - it would mean first slowly killing off its forward velocity in space, which would drop it into the sun before it could get up to speed the other way.

Answer 4

I never heard of retrograde motion being a sign of the end in any tradition. In astrology, retrogrades refer to the principle of that body expressed as turning inward instead of expressing as outward.

Retrograde is an apparent motion, not a motion that happens literally in reverse. When we watch a planet like Mars as we pass it in our orbit, it appears to go the opposite direction. In fact, the orbit of Mars is exactly what it had been all along, an imperfect ellipse, just like the Earth has an imperfect ellipse. That apparent reversal of motion is only temporary, and Mars resumes its course from west to east over the course of the year.

Earth also retrogrades when viewed from other planets in our solar system. We would not sense that retrograde. And it will appear differently from Mercury than it would from Jupiter, or any other planet, asteroid, or comet.

Answer 5

The retrograde motion of planets is purely subjective. Planets do not move backwards in their orbits. They appear to do so periodically because while our Earth is orbiting the Sun with the other planets, they are all orbiting at different rates. So, depending on where the Earth, or for example Mars is in its orbit, Mars may appear to be moving backwards in relation to the Earth. Does that make sense? If you were observing Earth from Mars over the course of a year, the Earth would appear to go retrograde periodically.

So, retrograde motions of planets happen all the time, but only when observed from Earth. All the planets are moving in the same direction constantly around the sun. Now, to Astrologers, a retrograde planet might not be the end of the world, but it is sometimes inconvenient.

I hope that answers your question.

Answer 6

RE:
retrograde motion- earth?
will the earth ever forgo a retrograde motion. was reading up that this is something that happens to other planets, recently to Mars.
also a sign of the end of the world in certain religious beliefs!!!

Answer 7

Yes, the Prophet Mohamed foretold that the rising of the sun from the West will be a sign of the end of times. How it will happen though is not clear. It could be through Earth going through retrograde motion, it could be through a polar reversal, or it could happen in some other way. What is certain is that the sun will rise one day on planet Earth from the West and from then on it is stated that God will stop accepting people's repentance from then and that the end of the world and life as we know it will be upon us.

Answer 8

I got these answers from the above muslims' comments and answers.
By the way I'm a muslim too and the above muslims are all scientifically minded.
The sun would in the future to be said to rise in the west because:-
1) shift in the tilt of the earth's axis.
2) polar reversal.
3) retrograde motion or retrograde rotation of the earth.

This is all I can say if you non muslims need science to believe it.

Answer 9

retrograde motion is only an apparent movement backwards as a result of standing at a point that is moving. ie the Earth. You can get a simmilar type of illusion when on a train if a train next to yours starts to move you feel as if you are moving in the opposite direction.

Answer 10

1