# Reversing rotation of Earth, effects on satellites and satellite-based communications

So, awhile back I asked this question Reversing the rotation of the Earth, effects

In it I said that,

We can probably assume that Dr. Doofenshmirtz wanted this to happen quickly, within a day, so from normal rotation speed to reverse rotation within 24 hours. We can also probably assume that he wanted to get to the same speed in reverse, so from 460 m/s or 1000 mph, in our current direction, to zero, to 460 m/s or 1000 mph in the other direction all within 24 hours.

I wanted to know what the large scale effects on the Earth would be. I received the following in an excellent answer by Penguino.

If the evil doctor can somehow decelerate and accelerate all the interior and exterior parts of the earth in unison (including the sea) - for example some hyper-technology tractor beam - then there should be no ultra-catastrophic problems. The surface acceleration required to do the reversal in 24 hours is around 0.01 m/s2 , or about 1/1000 of the acceleration due to gravity. If you were standing still on the surface you probably wouldn't even notice it. But there might be subtle effects due to the temporary reduction in centripetal force on the earth's crust that could result in earthquakes, volcanic activity etc. Note that in the future, tides would occur around every 11-12 hours rather than every 12-13 hours. And I almost forgot to mention, if all rotational motion is 'near-instantaneously' reversed then the earth's generated magnetic field would also want to switch polarity. This might have interesting effects on the ionosphere, national grids and the like.

If the Earth's rotation was reversed based on the above stipulations, what would happen to our satellites and satellite based communications (GPS, Internet, ect.) during this day. Bonus points for long term effects/how long would it take for us to recover.

• Reminder to close-voters: The problem cannot be fixed if the OP is not made aware of it. Jul 11 '18 at 18:41
• That being said, questions asking for the changes to all of human society because of some event/object/whathaveyou are almost universally closed as too broad. There's simply too many pieces to a society for a post on a Q&A site to address it all and meet the expectations of a good answer. Jul 11 '18 at 18:43
• To add to @Frostfyre's comment and to have a little fun: are you interested in architecture? Tall buildings? small buildings? Dams? Dog houses? Parks? Romantic liasons? Social media? The value of the Eritrean nakfa (money)? Little Jimmy's soccer practice? Lipstick sales? Native fetility dances? War? Religion? How I'd pick my cherries? "Human society" is mind-boggelingly enormous (aka, "too broad"). Is there something (really) specific you're interested in? Jul 11 '18 at 19:24
• Now we're talking! VTR! Jul 11 '18 at 23:26
• @JBH what does VTR mean? Jul 12 '18 at 1:30

As far as the satellites go, the question is whether or not their orbits changed with the new rotation. If not, formerly geosynchronous satellites would race off westward at 2,000 miles an hour.

Regardless of the speed at which the rotation was reversed, "Noon" may no longer be at the right time of day. Clocks would not change, but unless the rotation was put back in sync as before, the sun may no longer appear directly above a time zone when the clock reads 12. Whether or not the various measurement organizations would want to re-calibrate "noon" to match the new positioning would be an interesting debate.

Getting used to the new direction that the sun comes up will certainly take some time. There'd be some new poems made, and Japan would have to get used to being the Land of the Setting Sun.

Everyone's GPS, satellite radio, TV, internet... anything that relies on the satellite network would fail almost instantly. To that end, SpaceX will suddenly become terribly successful. Airlines would shut down pretty much immediately as systems start to fail. Regions powered by lots solar power would experience drops in energy production as solar panels which track the sun start tracking the wrong direction.

If you don't accelerate the insides of the earth at the same rate as the outside, there are going to be some MASSIVE magnetic shifts. Compasses would likely stop working correctly, and we could have some incredible aurora.

Physicists working on neutrinos are going to notice that suddenly they can't beam neutrinos to different parts of the world like they used to be able to. Astronomers' telescopes will stop tracking stars... I'm sure there are more, but the list truly does go on forever.

• Could you provide a hint on why GPS fails? Their orbits are much faster than double rotation speed, and I think things traveling 2k mph east could currently use GPS.
– user25818
Jul 11 '18 at 19:12
• @notstoreboughtdirt Because GPS relies on determining your distance from a fixed cluster of satellites. Sure, you might still get signal, but Google Maps is going to have a hard time figuring out which exit you should get off on when you're shown as going 2000mph Jul 11 '18 at 19:19
• And I'm actually still not sure you would get signal. If you remember the early days of Tom Toms and such, it took forever to get a signal. If satellites are suddenly rising and setting, its going to be pretty difficult to keep a signal locked down Jul 11 '18 at 19:24
• My understanding is that most speed algorithms use displacement between readings rather than only Doppler to assess speed, so would generally arrive at a correct value after the first one. They would rise and set 3 times a day instead of twice I think, but I'm not sure if that is enough to break things and I think the ability to handle moving east fast implies it wouldn't at least near the poles, do you have any further reading?
– user25818
Jul 11 '18 at 20:09
• Interesitngly enough, that may also trip the "no muntiions" clause in your GPS. There are rules put on GPSs to make them be deemed "consumer grade" rather than "munitions grade." They're basically designed to make it hard to use a consumer grade GPS to guide a cruise missile. The rules have had some ambiguity, so many manufacturers are conservative. Under the conservative rules, a GPS may decide you are traveling fast enough to be a cruise missile and refuse to provide position updates. Jul 12 '18 at 4:37

Regarding Satellites: Short-term, pretty much everything goes down. GPS goes haywire, same for all satellite communication. Mid-term, anything not requiring geostationary satellites or similar ones (like satellites in Molniya orbits, i.e. Russian telecommunications satellites) could probably be restored to functionality. Not sure if GPS devices would need an update, though.

In the long term, we'll need a few spacecraft to clean up the GEO ring. There are hundreds of live and dead objects there and in the 17° inclination range, all orbiting in the same direction. If we want to use the ring ever again, we need to do some housecleaning first. That means moving hundreds of satellites to a graveyard orbit significantly higher than the standard graveyard orbit (because otherwise, we risk high-speed collisions). That would be a monumental project, but once we're done everything could go back to normal.

In the meantime, we'd probably use Molniya-type orbits for telecommunications, which are relatively easy to adapt to.