# Planet Mars is rotating the other way? **URL:** \ **Category:** Factual Questions\ **Created:** [October 26, 2003, 3:18am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606 "2003-10-26T03:18:10Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Z\_Al](https://avatars.discourse-cdn.com/v4/letter/z/41988e/32.png) [@Z\_Al](https://boards.straightdope.com/u/Z_Al)\ **Post date:** [October 26, 2003, 3:18am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/1 "2003-10-26T03:18:10Z")
I heard from a friend that he heard this thing on the news claiming that planet Mars is now rotating the opposite way now (so now the sun rises from the west instead). This shocked me pretty seriously so I am here to check on the validity of this piece of news. Thanks from one of the teeming millions. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [October 26, 2003, 3:23am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/2 "2003-10-26T03:23:28Z")
It’s not the rotation of Mars that has reversed. It’s the apparent direction of Mars as it moves acros the sky. It’s called _retrograde_ motion, and it’s an illusion caused by the Earth having a higher angular velocity. [Link.](http://mars.jpl.nasa.gov/allabout/nightsky/nightsky04.html) ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [October 26, 2003, 3:28am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/3 "2003-10-26T03:28:09Z")
Venus rotates on its axis in the opposite direction of us. But, all the planets revolve around (orbit) the Sun in the same direction. Our position relative to them and the Sun causes some odd APPARENT movements at times. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [October 26, 2003, 3:33am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/4 "2003-10-26T03:33:05Z")
Mars did reverse its course across the sky, if that is what your friend heard; this happens every two years, and is called a ‘retrograde loop’. [http://www.spaceweather.com/delights/mars2003\_Loop.html](http://www.spaceweather.com/delights/mars2003_Loop.html) However it is just an illusion; the planet does not really reverse its course, it just seems to as the Earth sppeds by in its faster orbit. And the spin of Mars itself is unaffected. * * * SF worldbuilding at [http://www.orionsarm.com/main.html](http://www.orionsarm.com/main.html) ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [October 26, 2003, 3:35am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/5 "2003-10-26T03:35:36Z")
[A demo!](http://www.astro.uiuc.edu/projects/data/Retrograde/) [It helped to prove the Heliocentric model.](http://www.scienceu.com/observatory/articles/retro/retro.html) ---
**Author:** ![Z\_Al](https://avatars.discourse-cdn.com/v4/letter/z/41988e/32.png) [@Z\_Al](https://boards.straightdope.com/u/Z_Al)\ **Post date:** [October 26, 2003, 3:36am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/6 "2003-10-26T03:36:12Z")
Thanks for the replies… What I meant is not the direction across the sky, but rather its orbit around its own axis. So no such phenomena took place, I deduce? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [October 26, 2003, 3:37am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/7 "2003-10-26T03:37:32Z")
> [@](#): > > \*Originally posted by Z\_Al \* > \*\*Thanks for the replies… What I meant is not the direction across the sky, but rather its orbit around its own axis. So no such phenomena took place, I deduce? \*\* No. ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [October 26, 2003, 3:38am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/8 "2003-10-26T03:38:25Z")
A planet ROTATES (spins) on its axis. It REVOLVES (orbits) around the Sun. ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [October 26, 2003, 4:58am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/9 "2003-10-26T04:58:51Z")
If a planet stopped rotating and then reversed direction, I believe it would rip itself to shreds. And what force could cause that to happen in the first place?! ---
**Author:** ![Joe\_Random](https://avatars.discourse-cdn.com/v4/letter/j/e8c25b/32.png) [@Joe\_Random](https://boards.straightdope.com/u/Joe_Random)\ **Post date:** [October 26, 2003, 5:06am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/10 "2003-10-26T05:06:32Z")
> [@](#): > > \*Originally posted by Early Out \* > \*\*And what force could cause that to happen in the first place?! \*\* Why, [Planet X](http://armageddononline.tripod.com/planetx.htm), of course! What I wouldn’t give for a tin-foil-hat smiley to go along with that link ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [October 26, 2003, 5:28am UTC](https://boards.straightdope.com/t/planet-mars-is-rotating-the-other-way/209606/11 "2003-10-26T05:28:05Z")
> [@](#): > > \*Originally posted by Joe Random \* > What I wouldn’t give for a tin-foil-hat smiley to go along with that link Like this? ;j