Moon and Mars Change places

[Mr. G]

What if on January 1 2004, the Moon and Mars change places? Mars starts orbiting the Earth at the same distance of the moon. While the Moon orbits the sun in mars's old orbit.
What chaos would result?

[Straha]

a closer mars means that maybe space advocates would gian strengh and martian terraforming beginnign in 2020 is possibleh

[NapoleonXIV]

The main and immediate problem on Earth will be tides. Mars is a small planet, but substantially bigger than the moon. Those areas with big tides will be inundated immediately with fairly large loss of life and property. All areas with tides will be affected as even small tides will become substantially larger. Not pleasant disasters, but the earth will probably survive.

Much more problematic will be the effect on Ocean currents. I don't know what these will be.

Most all of our satellites will be lost as the tides will pull them out of their present orbits.

Mars, unlike the moon, has a magnetic field. If this doesn't seriously disrupt the Van Allen Belts and expose us to radiation it will probably disrupt global communication networks on the ground and fry whatever electronics remains above.

[Amerigo Vespucci]

ASBs need to take away the gravitational effects, or things would get really nasty. The tides would pretty much wipe out all coastal life on earth, otherwise. Barring gravitational effects, Mars would provide a slightly more hospitable short-range target for space programs, and we might see a slightly larger space program from all space-faring nations, but I can't see much beyond a small station. The gravity well would be too energy-prohibitive for much more.

[DominusNovus]

Wouldn't this almost create a double planet system? What would happen to Mars? Would being closer to the Sun melt the ice caps much?

[NHBL]

There will be massive devastation of the Earth's seashores, as Mars' much greater mass produces tide far more powerful than the Moon. Most coastal cities are simply washed away.

[David S Poepoe]

Well now, won't NASA's probes "Spirit" and "Oppurtunity" end up being a waste of money. Launched to land on Mars they end up landing on the moon.

[Norman]

don't forget about volancos on both planets. soon mars would probably have a thicker atmosphere and more water as the greater geologic activity wracked it.

[Leej]

The ASBs would definatly need to get rid of gravity effects as well as the standard mass-hysteria.
Otherwise we would have huge tides, mega earthquakes and volcanic erruptions and probally as a result of all these all of the other natural disasters you can think of.

Mars in the same orbit as Earth could be terraformed quite easily- if it had been this close to the sun from the start it would probally be life supporting.

[NomadicSky]

Now it's been more than two years since this was posted, but what would the world and Mars be like today had this happend?

[Saladin]

Er ... I'm not sure, but I *think* that Mars would be inside the Roche limit, if it is, then we woud now have a *glorious* ring system around the equator. However, we wouldn't see it as all the asteroid strikes generated by Mars breaking apart would've killed us all :D

Edited for spelling

[NomadicSky]

So this would have probably been one of the last things that many people would have ever seen.

[Saladin]

now THAT is one KEWL image :)

[Tetsu]

That is a badass and slightly disturbing pic, Indigo. :eek:

[eschaton]

Mars would certainly *not* be inside the roche limit.

The tides would be far larger. Another thing to take into account is Tidal forces also cause the earth itself to pull and stretch slightly. Meaning we'd be looking at more earthquakes.

Honestly, the best bet is just to have the ASBS move Mars correspondingly further away from the sun, so it looks the same size in the sky as the moon. This would make the tidal effects pretty much null and void.

I'm surprised no one has discussed the effects on mars. All the extra solar radiation will heat up mars significantly. The CO2 in the polar ice caps will melt, along with whatever C02 permafrost is under the surface. This will speed along warming further. At first some water will sublimate into water vapor because of the low pressure. If there's enough air pressure (which from what I understand there will be), eventually a liquid water cycle would develop.

This isn't full terraforming on its own of course. There's no life on mars, no oxygen to breathe, etc. But if everything works out right you'd basically get an environment right off the bat some very hardy lichens, mosses, and desert plants could survive in. You'd be able to walk out in the open wearing nothing but a respirator, most likely. As the soil quality improves, forests would be possible within a span of a century or so. All humans would need to do is maybe whack Mars with another comet or two for volitiles, and then see about converting the C02 in the atmosphere into oxygen.

[Glen]

Mars, unlike the moon, has a magnetic field. If this doesn't seriously disrupt the Van Allen Belts and expose us to radiation it will probably disrupt global communication networks on the ground and fry whatever electronics remains above.


From here http://mgs-mager.gsfc.nasa.gov/

Mars does not presently have a global magnetic field but had one early in its life, similar to that of Earth. However, Mars does have very strong crustal magnetic fields, more than 30 times stronger than those of Earth.
Developed a detailed map of the magnetic fields of crustal sources.
The absence of magnetization in large impact basins allowed for the first time to establish the time of cessation of the Martian dynamo, more than 3.5 billion years ago.
The absence of a global magnetic field for billions of years has contributed to the erosion of Mars atmosphere by the solar wind and the loss of water.
Established a correlation of the horizontal component of the magnetic field with upstream solar wind dynamic pressure.

[Leej]

Some appropriatly geneticly engineered life could probalyl survive on Mars as it stands now.
Mars would not be a moon of Earth, Luna's centre of rotation is already pretty near our surface. With Mars...it'd be well out in space.

[Thande]

Mars would not be a moon of Earth, Luna's centre of rotation is already pretty near our surface. With Mars...it'd be well out in space.
True but we would still say that Mars is a moon of Earth. After all, we say that Charon is a moon of Pluto, and the centre of rotation between those two is also out in space.

[NomadicSky]

so mars would spin on it's own axis.
We'd see both sides of it:confused:

I wonder how scientist would have explained it?

[EvolvedSaurian]

So how long until colonies are started?

What kind of resources does Mars have?

[NomadicSky]

I found it here, (http://www.konsept.com.tr/serbestdusme/yasam/hobi/bk/resim.htm) I just googled Roche limit.

[drakkon]

So this would have probably been one of the last things that many people would have ever seen.

That reminds me of the last scene in the movie The Quiet Earth.

[Codeman]

so we would have a double planet orbit? that would be very cool but for this to happen doesnt there have to be a third object in the middle something like say the moon to anchor the planets together?

[Midgard]

so we would have a double planet orbit? that would be very cool but for this to happen doesnt there have to be a third object in the middle something like say the moon to anchor the planets together?

There doesn't have to be a third object - simply the center of gravity may lay outside Earth's body, similar to Pluto/Charon orbit, where the center of gravity is actually a point in space in between the two. Interestingly enough, this is also the case with Jupiter and the Sun, and is the basis for "wobble" technique used by astronomers to determine presence of extrasolar planets.

[fortyseven]

There doesn't have to be a third object - simply the center of gravity may lay outside Earth's body, similar to Pluto/Charon orbit, where the center of gravity is actually a point in space in between the two. Interestingly enough, this is also the case with Jupiter and the Sun, and is the basis for "wobble" technique used by astronomers to determine presence of extrasolar planets.

One discredited theory for stellar wobbling was that the stars were drunk but no alcohol was ever found in the spectral lines.

[Midgard]

One discredited theory for stellar wobbling was that the stars were drunk but no alcohol was ever found in the spectral lines.

Actually... I believe not long ago a large cloud of what is essentially alcohol was found in outer space. Maybe that was the real reason for jump-starting the Russian space program :eek: :D

[fortyseven]

Actually... I believe not long ago a large cloud of what is essentially alcohol was found in outer space. Maybe that was the real reason for jump-starting the Russian space program :eek: :D

I hadn't heard of that.


You mean this?linky (http://www.abc.net.au/science/news/space/SpaceRepublish_1607946.htm)

[Midgard]

I hadn't heard of that.


You mean this?linky (http://www.abc.net.au/science/news/space/SpaceRepublish_1607946.htm)


That's it!

[Leej]

There doesn't have to be a third object - simply the center of gravity may lay outside Earth's body, similar to Pluto/Charon orbit, where the center of gravity is actually a point in space in between the two. Interestingly enough, this is also the case with Jupiter and the Sun, and is the basis for "wobble" technique used by astronomers to determine presence of extrasolar planets.
I don't think its the case between Jupiter and the sun. Jupiter will orbit quite a bit off centre but certainly not 'outside' of the sun. That takes one of those really big red hot super jupiters.

[Thande]

I don't think its the case between Jupiter and the sun. Jupiter will orbit quite a bit off centre but certainly not 'outside' of the sun. That takes one of those really big red hot super jupiters.
Yeah, Leej is right, Midgard - although I think you knew what you were talking about, you just didn't state it that clearly. The centre of rotation still lies within the sun, but not at the centre of the sun.

I always find it a bit bizarre that some (astronomers!!) say how strange it is that they've discovered so many super-larger-than-Jupiter planets orbiting very close into their stars, using this technique. Well DUH, they produce the largest wobble, so obviously they'll be the ones you discover first :rolleyes:

[Midgard]

Yeah, Leej is right, Midgard - although I think you knew what you were talking about, you just didn't state it that clearly. The centre of rotation still lies within the sun, but not at the centre of the sun.

I always find it a bit bizarre that some (astronomers!!) say how strange it is that they've discovered so many super-larger-than-Jupiter planets orbiting very close into their stars, using this technique. Well DUH, they produce the largest wobble, so obviously they'll be the ones you discover first :rolleyes:


Actually, accordingly to this (http://en.wikipedia.org/wiki/Jupiter) article at Wikipedia,

Jupiter is 2.5 times more massive than all the other planets combined, so massive that its barycenter with the Sun actually lies above the Sun's surface (1.068 solar radii from the Sun's center).

meaning that the center of gravity between Jupiter and the Sun is actually 0.068 ABOVE the Sun's surface. Given that in cosmic terms, it is still a very small distance, it is no surprise that it takes much larger "wobble" for extrasolar worlds to be detected though.

[Alcuin]

Surely, with a planet the size of Mars (eight times the mass of the Moon), a mere quarter million miles away, we'd become a double planet system, tidally locked so that the same face of Earth remains facing mars while the same face of mars faces earth (Earth's tidal effect on the moon has the same effect in otl).

This would mean...

Lower, slower tides affected only by the sun. Possibly even no appreciable tides at all. (Yes, it's a paradox, because the tidal effect locks us together, the effect on the sea is less visible.)

Earth bulges toward mars and vice versa.

The day becomes a month long (since Earth turns to face the sun on a 28 day cycle).

Earth and marsquakes, volcanoes, thicker atmosphere on mars.

Oh yes, and there would be an area of earth where the sun never shone (always being in the shadow of earth or mars).

[Anthony Appleyard]

Oh yes, and there would be an area of earth where the sun never shone (always being in the shadow of earth or mars).
Huh?? I can't see how that would happen.

[NomadicSky]

If it did happen, that would really suck.

[NomadicSky]

If it did happen, that would really suck.

[Alcuin]

Huh?? I can't see how that would happen.

Well... it depends on the direction in which the Earth-Mars system rotates. Looking again, it seems unlikely, but there is a place that constantly faces toward Mars, in the "morning" it'll get angled sunlight, and in the evening, but every "day" there will be a solar eclipse in that place... and it'll last longer than they normally do because Mars is roughly twice the radius of the moon so its umbra is bigger. (And there won't even be a corona because the disk of mars is more than big enough to block out the sun.

[Tizoc]

Well... it depends on the direction in which the Earth-Mars system rotates. Looking again, it seems unlikely, but there is a place that constantly faces toward Mars, in the "morning" it'll get angled sunlight, and in the evening, but every "day" there will be a solar eclipse in that place... and it'll last longer than they normally do because Mars is roughly twice the radius of the moon so its umbra is bigger. (And there won't even be a corona because the disk of mars is more than big enough to block out the sun.
I don't see how there could be a place that constantly faces Mars - it would need Mars moving very fast on its orbit - like ~24hrs to complete orbit around Earth... And besides, if this was possible then how it comes that there is no place on Earth that faces Moon all the time, hmmm?