Terraforming Mercury

Terraformer · 2007-12-01 06:52:18

Of all the planets, I'd say Terraforming Mercury is the simplest. All that needs to happen is big holes need to be dug (really big ones) down near the iron core. Then, once we reach a point where the gravity is imilar to Earths, Mercurys meager atmosphere of hydrogen will fill the gap. Find some way of skimming CO2 off *nearby* Venus, react it with the Hyrogen, and you get Carbon for an elevator to the surface (or elevators) and bolstering Mercurys magnetic field, and Water. React the water with the UV light at the surface. The heavier Oxygen will sink down and the Hydrogen will rejoin the surface. Import some buffer gas, it's only a small atmosphere to start with after all, could possibly be imported from Earth, and you have an atmosher to start living in. Later it may be possible to get rid of a lot of the surface and just keep a layer seperating the molten iron core from the surface. The tunnels could be dug in rooms, with the 1g or slightly higher enviromnt for exercising in, with a 0.8g enviroment to be sold to rich people to fund the Terraformation.

samy · 2007-12-01 12:44:30

I don't think you'll get 1g anywhere on Mercury, no matter how deep you go.

In fact, if you dig all the way to the exact centerpoint, you will have 0g.

Terraformer · 2007-12-01 14:27:31

Except, even if the molten iron core wasn't a problem, you'd actually have half the surface g all around you (from samy's idea..

Simple physics, Newtonian I think. As you go towards the center of the Earth, gravity increases. It's responsible for interesting relativistic effects, like time running slightly faster on top of a hill, due to the reduced gravity. And it doesn't just work on Earth. Other planets with core compresion as well.

samy · 2007-12-01 14:44:54

Well, since you'd have 0.5g upwards and 0.5g downwards, it would all balance out to 0g. After all, if you're in the centerpoint, which direction are you going to fall in? Up or down? Answer: neither. Centerpoint has 0g, and you'd stay floating there, because there's equal mass in every direction, cancelling out the opposite directions.

Tom Kalbfus · 2007-12-01 15:44:27

I don't think you'll get 1g anywhere on Mercury, no matter how deep you go.
In fact, if you dig all the way to the exact centerpoint, you will have 0g.

Mercury has the same gravity as Mars, that means if you dug a hole thats 328 km deep, you could have an atmosphere at the bottom of 1 bar of air pressue and one millionth of a bar at the top, a similar sort of thig can work out on Mars. The only problem with Mars though is that its atmosphere is mostly carbon-dioxide and that carbon dioxied will concentrate at 1 bar 328 km deep in the hole. Fortunately for Mercury, it has a trace atmosphere of oxygen and no carbon-dioxide, if any natural atmosphere forms at the bottom of the hole, it will be one of oxygen. Also having a hole that deep keeps it in shadow much of the time, and with the Sun looming so large in the sky of Mercury, this could be a good thing.

samy · 2007-12-02 00:54:27

Of course, 300+ km inside Mercury might be very uncomfortable due to heat...not to mention the sheer difficulty of creating a 300+ km long tunnel. It's so far beyond any current technology we can conceive it's not even funny. We're not even able to dig 10km deep on our homeworld, let alone 30 times deeper on another celestial body by remote operated probes.

Might be doable someday, but definitely not in our lifetimes.

I also question whether Mercury has enough atmosphere to provide that 1 bar...is there enough atmosphere on the surface to fill that hole entirely?

I did a quick and dirty calculation that suggests that if you gathered up the entire atmosphere of Mercury (for which I got a rough figure of 560 000 kg) and placed it over one spot, that spot could be a maximum of 5.6 square meters if we wanted to provide 1 bar...any larger than 5.6, and the mass is insufficient to provide 1 bar anymore.

(Although, this NASA page says the total atmosphere mass is in fact less than 1000kg, which is even worse...)

Terraformer · 2007-12-02 04:18:47

Finally, some information on the mass of Mercurys atmosphere, which is mainly hydrogen and helium collected from the solar wind. CO2 imports from Mercury would be neccesary.

Like I said, simple physics. Gravity increases as you move towards the center of a body of mass, and decreases as you move away from the center. I don't know the equations so I can't work out how far down you need to dig on Mercury to get close to 1g.

Before digging the hole we need to find the deepest crater on Mercury.

samy · 2007-12-02 04:31:00

Like I said, simple physics. Gravity increases as you move towards the center of a body of mass, and decreases as you move away from the center.

Like I said, that's oversimplified and inaccurate physics. When you get all the way down to the center, you'll actually get 0g. The gravity will be dropping towards the center of the planet, because you're starting to have the same mass all around you, pulling you equally in all directions and cancelling each other out.

I haven't calculated what the tip-over depth is, where gravity will start decreasing with depth rather than increasing with depth, but that will happen at some point.

Terraformer · 2007-12-02 06:22:58

Well, obviously. I said it will increase as you move towards the center. I didn't say there will be crushing gravity at the center.

I don't think it's possible to get to the 0g point or the tip over point on Mercury unless you have a craft that can travel in liquid Iron. Mercury has a massive molten Iron core with a thin solid mantle/crust that is about 1/10 as thick as the diameter of the core.

Tom Kalbfus · 2007-12-02 09:04:38

Of course, 300+ km inside Mercury might be very uncomfortable due to heat...not to mention the sheer difficulty of creating a 300+ km long tunnel. It's so far beyond any current technology we can conceive it's not even funny. We're not even able to dig 10km deep on our homeworld, let alone 30 times deeper on another celestial body by remote operated probes.
Might be doable someday, but definitely not in our lifetimes.
I also question whether Mercury has enough atmosphere to provide that 1 bar...is there enough atmosphere on the surface to fill that hole entirely?
I did a quick and dirty calculation that suggests that if you gathered up the entire atmosphere of Mercury (for which I got a rough figure of 560 000 kg) and placed it over one spot, that spot could be a maximum of 5.6 square meters if we wanted to provide 1 bar...any larger than 5.6, and the mass is insufficient to provide 1 bar anymore.
(Although, this NASA page says the total atmosphere mass is in fact less than 1000kg, which is even worse...)

If you have the capability of digging such a hole, providing the atmosphere should be no problem. Mercury probably has lots of oxygen bound up in its rocks.

Terraformer · 2007-12-02 09:20:05

Have you compensated for the fact that the gravity would be higher that far down, so you wouldn't need as deep a hole?

Tom Kalbfus · 2007-12-02 12:37:08

Have you compensated for the fact that the gravity would be higher that far down, so you wouldn't need as deep a hole?

Lower, gravity only gets higher if you squeeze the planet so that all of it is underneath your feet. If Mercury was a hollow shell and their was a black hole at the center with Mercury's mass, then gravity would get higher as you got lower. But since the deeper you go the more of the planet is above your head and the less below, gravity actually gets lower.

Antius · 2007-12-02 16:28:56

On Earth, the deepest hole ever drilled was in the Kola perninsula in Northern Russia. It went down about 15km. The problem with drilling deep holes on Earth is that the cost of doing so increases exponentially with depth. most drilling is associated with oil or geothermal research, so beyond a certain depth the cost is so high that it is no longer justifiable. Thats not to say that we couldn't drill much deeper holes if we had all the money in the world and a good reason to do it.

But what the hell is the point of drilling a 200 mile deep hole on Mercury? Never mind the fact that the temperature just a few feet below the surface is hot enough to boil water. Mercury really is a candidate for paraterraforming. Erect a glass greenhouse on the surface and tint the windows so that 90% of incoming light is refected back into space and you have Earth normal sunlight underneath.

A more natural approach would require an orbital sunshield or billions of tiny aluminium balloons in the upper atmosphere. The slow rotational period would be a problem. The planet would also need a powerful synthetic magnetic field in order to deflect the solar wind during periods of high solar activity. Mercury's existing field is compressed all the wayy down to the surface during storm events.

Austin Stanley · 2007-12-06 20:51:02

The problem with para-terraforming Mercury is that the amount of solar energy it receives is massive. It would be hard to create a structure that could survive the intense thermal roasting it receives during its long day (hot enough to melt lead) and then the shock of cold during its night. While possibly not impossible to achive, almost all plans I have seen seek to avoid being roasted in the sun somehow. The same issue exists for an orbital shield of some sort as well. That close in to the sun it become difficult to deal with all the radiation (thermal and otherwise).

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Which is why I do think mega-excavation is an excellent idea. While it is doubtful that you could dig to the point where Mercuries gravity equals 1G (if such a point actually exits), you could dig some very deep pits at the poles to provide yourself with a secure shelter from the sun.

Such a 'hole' might not actually be that difficult to create. As I pointed out before the sun emits massive quantities of energy when you are as close as Mercury is. A few mirrors held in place by Mercuries gravity and solar pressure at the poles could be used to melt and vaporize huge quantities of Mercuries surface, digging the whole for you.

To me the big question is why. Mercury's core probably contains good quantities of useful metals, but that is hardly unique in our solar system. It would be a good place to observe the sun, but that is probably better done unmanned. Maybe it would serve as a decent staging platform for efforts to terraform Venus, or a manufacturing plant for anti-matter or possibly solar sails.

Antius · 2007-12-07 10:18:55

The problem with para-terraforming Mercury is that the amount of solar energy it receives is massive. It would be hard to create a structure that could survive the intense thermal roasting it receives during its long day (hot enough to melt lead) and then the shock of cold during its night. While possibly not impossible to achive, almost all plans I have seen seek to avoid being roasted in the sun somehow. The same issue exists for an orbital shield of some sort as well. That close in to the sun it become difficult to deal with all the radiation (thermal and otherwise).

Not that difficult in a vacuum. Give the glass a tint just a few atoms thick and most of the sunlight will be reflected into space.

Charged particle radiation would be more of a problem.

JoshNH4H · 2007-12-15 16:02:49

Actually, I think a combination of the two would be best. Dig a 10-20 km hole, at the bottom if you're more than 10 or 20 km n/s of the equator, you NEVER get hit w/direct sunlight. Have it 1 km on, 1 km off, then you're golden (like this)

But this is going too far. Why not go down 1km? Why build shafts at all? Why not mine mercury w/ automated machines, and get the stuff from orbit? Venus, once you get it to a more-or-less earthlike state is somewhat stable. But mercury? Mercury will never be. Mercury should be the metal mine of the system. Instead of using insanely long shafts to build overheated and vulnerable habs, let's experiment w/ solar powered core mining.

karov · 2007-12-17 13:36:36

Mercury -- import solar hydrogen mined magnetically. The oxygen is in the crust in form of silica + alumina. with H = water + silicone and aluminum. Make from the Si and Al all the photovoltaic+shade you need.

The N, C , etc. import from Venus. ( Where most of the CO2 is turned in H2O and C exported).

The solar hydrogen moves with velocities dozens of times higher than the escape velocity of the deepest inner system ( aside Earth) gravity well - Venus. Importing the hydrogen - needed to change Venusian atmospheric chemistry - taking it from the Sun, gives you all the energy to do Venus terraforming, AND simultaneously to move the excess chemicals from Venus to: Mercury, Moon, Mars, Ceres, Vesta, Pallas, Hygeyia, Io, Europa, Callisto, Ganymede...

...if you have the plasmics / plasma tech, like electoniCS, photoniCS.../ to move around as much staff - H, C, N, Al, Si... you also don`t need worlds roofing, cause good plasmic piplelines means good plasmoid atmosphere retention

Antius · 2008-02-15 07:05:36

Actually, I think a combination of the two would be best. Dig a 10-20 km hole, at the bottom if you're more than 10 or 20 km n/s of the equator, you NEVER get hit w/direct sunlight. Have it 1 km on, 1 km off, then you're golden (like this)
But this is going too far. Why not go down 1km? Why build shafts at all? Why not mine mercury w/ automated machines, and get the stuff from orbit? Venus, once you get it to a more-or-less earthlike state is somewhat stable. But mercury? Mercury will never be. Mercury should be the metal mine of the system. Instead of using insanely long shafts to build overheated and vulnerable habs, let's experiment w/ solar powered core mining.

A terraformed Mercury would require active methods for blocking out/reflecting unwanted sunlight. This might include a combination of orbital sunshade(s), relective high-atmospheric microballoons, high atmosphere sulphur dioxide injection and the placement of high albedo material in equatorial regions.

None the less, I like the idea of a sinkhole world. Getting sunlight into the sinkholes would be easy enough to achieve using mirrors. The long day length would be problematic for some crops but would not effect deciduous trees, as they lose their leaves in winter time anyway.

Mercury has a shallow axial tilt, so above a certain lattitude the bottom of a sinkhole will never recieve direct sunlight. With holes 20km deep, the atmospheric pressure at the bottom of the sinkholes would be roughly 10 times greater than the pressure at the top.

undormant · 2015-06-03 07:00:52

If we could slow the rotation of Mercury so that its tidally locked to The Sun we could create an atmosphere which would leave a nice large terminator/habitable zone between the night and day side.

A place where the sun is either always rising or always setting, a permanent summer.

Either side of this zone would be a thin extreme zone. One side 50 degrees desert the sun boiling large in the sky, the other Antarctic conditions forever in darkness.

Humans being as we are would live in these extremes, push it, as we do on Earth.

Then you'd have a huge sun facing side of the planet that you really don't want to go near!

The other side frozen, but I do wonder what the hot air currents would do and whether a dark side polar cap would form due to recent predictions about hot air dropping at that point and cold air rising. Might get a lake or melted part at that point?

Antius · 2015-06-26 08:04:43

In the absence of an atmosphere, the high day time temperatures of Mercury can be dealt with by covering a colony with a reflective aluminium foil sheet. The sheet can be holed to let in the required amount of light. Waste heat can be stored within the rock mass beneath the colony and then pumped into the habitat during the Mercurian night. With virtually no axial tilt and no seasons, the daily insolation on Mercury follows straight and predictable bands as one heads north or south from the equator. At 80 degrees north, insolation would be about the same as Earth equatorial.

The relatively high gravity of Mercury is also useful for para-terraforming, as a glass-steel dome installed above a large crater would balance the internal air pressure against its own weight. If the dome could be anchored over a 20km deep crater, with an air pressure of 0.5 bar at the bottom, the pressure at the top would be 0.05bar and could be balanced against a weight of 1.3 tonnes/m2 in Mercury gravity. This structure could therefore be weighted down using water or rocky material. In the event of a decline in internal pressure, the structure would drop ballast therefore maintaining the balance of forces. This would allow plenty of time for any leak to be checked.

The high day-night temperature variation on Mercury raises the interesting possibility of storing heat and cold in rock bodies and producing continuous power using an S-CO2 supercritical cycle.

Mars_B4_Moon · 2022-03-21 07:17:01

Older article

How Do We Terraform Mercury?
https://www.universetoday.com/128531/terraform-mercury/

more recent news

'There Could Be 16 Quadrillion Tons Of Diamonds On The Planet Mercury Suggests New Research'
https://www.forbes.com/sites/jamiecarte … -research/

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#1 2007-12-01 06:52:18

Re: Terraforming Mercury

#2 2007-12-01 12:44:30

Re: Terraforming Mercury

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#4 2007-12-01 14:44:54

Re: Terraforming Mercury

#5 2007-12-01 15:44:27

Re: Terraforming Mercury

#6 2007-12-02 00:54:27

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#7 2007-12-02 04:18:47

Re: Terraforming Mercury

#8 2007-12-02 04:31:00

Re: Terraforming Mercury

#9 2007-12-02 06:22:58

Re: Terraforming Mercury

#10 2007-12-02 09:04:38

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#11 2007-12-02 09:20:05

Re: Terraforming Mercury

#12 2007-12-02 12:37:08

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#13 2007-12-02 16:28:56

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#14 2007-12-06 20:51:02

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#15 2007-12-07 10:18:55

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#16 2007-12-15 16:02:49

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#17 2007-12-17 13:36:36

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#19 2015-06-03 07:00:52

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