There’s not enough CO2 there. Doesn’t seem like a problem to me; just import carbon and oxygen (and hydrogen) from carbonaceous asteroids in the belt. And of course, they have to throw this in:
If you believe it’s possible to terraform Mars, you also must believe in human-caused climate change, because it’s the same process. Even if it’s impossible to terraform Mars, it’s clearly possible to areoform the mid-latitudes of Earth. Because people are doing it.
Ummmmm…no. We’re not.
Meanwhile, Tim Fernholz says we’re going to have to be careful to not contaminate the water there.
It would be shortsighted and wasteful to terraform Mars. It already lost one atmosphere, why throw away a second (plus more if it’s maintained for a long time)? Just because there are a lot of volatiles available in comets doesn’t mean future generations wouldn’t curse us for being so wasteful of them. Manmade habitats might be a better use.
Whoever wants to use those resources will presumably have to bid for them.
Yes, any new atmosphere we create on Mars will dissipate away, too, for the same reasons the old one did.
But it will take a long time – tens, hundreds of thousands of years – just as the old one did. It won’t happen overnight. Which will give plenty of time to put mitigation strategies in place.
But it will only be worthwhile if there’s enough of a human society in place on Mars to justify the effort, and pay for the cost. As Rand says, it will be a question of which customers can put in the highest bids for those resources.
It’s all a moot point anyway if it turns out that 0.38G gravity is shown to have serious sustained negative effects on human physiology and reproduction. If not, it will then be a question of establishing a large enough Martian society to pay for the effort.
Building a variable gravity station would likely be much cheaper than building bases on the Moon and Mars and it the technology would be very valuable for traveling and settling the solar system.
The delta-v to get material resources to locations in cislunar space is appreciable. The delta-v to get building material to the Moon and Mars is 0 m/s.
We will find out if living on the Moon and/or Mars is something the human body finds comfortable but it is a significant expense in time and money and there are a lot of uncertainties about whether or not anyone would want to subject themselves to those gravity environments after knowing what it is like.
Also, having a station support any Lunar and Martian activities could be beneficial to the overall efforts.
Delta-v is only one consideration but even considering it, simulating gravity could be a better way to transit to other destinations with more, or easy accessible, resources.
I very much get the damn the torpedoes mentality since progress appears so slow.
If you’re going to the trouble of terraforming mars, might as well see about installing a current loop around the equator to produce a magnetic field, reducing one factor that would strip away the atmosphere.
Adding a bit more iron in the core would likely help with holding the atmosphere, but would do nothing to prove AGW.
Paraterraforming.
One word: Paraterraforming
There’s that word again “believe”.
I remember reading abou tsticking a giant magnet at Sun- Mars L1 to shield the planet from the solar wind which strips away the atmosphere.
Anyway, habitats are better IMHO.
“Explore? Sure. Permanent scientific base? Absolutely. But cities? Oceans? Canals? Take a deep breath—because as far as anyone knows, you literally cannot do that anywhere else in the universe.”
You can have billions of people live on Mars, But probably not much more than millions by 2100.
And one has an “ocean” of water on Mars. This ocean is very shallow by earth standards. One can call them a bunch of shallow lakes, and have most the shallow lakes in the tropics of Mars.
–LISTEN, I GET it. You want to go to Mars. I want to go to Mars. (Sort of.) And the plan—it’s good. A rocket with people. A base on the moon. Then more rockets and more people. Start making fuel on the surface, maybe depot it along the way. An outpost becomes a base becomes a domed city. And then: terraforming.–
So you instead start with teraforming, and terraforming requires lots of underground water, which is pumped into a large crater.
Pump the water and people will come.
Their real estate is land and water rights. Of course they also have to the power and sewer hook up.
But location where there a lot water, and water is shallowest to surface [requiring less energy to pump] is important factor in terms of real estate location. Location, location, location.
One needs the water for air pressure. 10 meter depth on Earth is 1 atm, Mars has 1/3 gravity so 1/3 atm per 10 meter depth.
So diving bell on earth under 10 meter of water, the air pressure needs to 14.7 psi times 2 in terms of absolute pressure- 1 atm from atmosphere and 1 atm from water pressure. Swim uder water and under bottom of bell and you have 2 atm of pressure of air.
And this bell does not need to be strong, but needs enough force to balance the buoyancy- or air in the bell will provide buoyancy.
And force of buoyancy is also 1/3 on Mars- so if going to anchor a bell to bottom of a lake the cable strength is 1/3 but ballast or anchor mass is the same. And anything heavier than air inside the bell also acts as part of ballast- such as a brick floor or whatever.
And rather lake bottom and mass of submerged “house” one have a garage above lake- and driveway connecting to a street. Or roughly one could have many stories building and part building could be above the water. And basement room which controls ballast [submarine] and not need tied down by bottom of lake.
Other than structural aspects and lake will keep a fairly constant temperature, the lake provides outdoor space which people swim around it
Now, not thinking you have to have dome over the lake, but one could have dome and purpose dome is to reduce evaporation loss and allow enough pressure to so the lake water can warmer and not boil. Other options is have surface of lake being frozen and this requires water to be quite cold- requiring wet or dry suits to swim in.
And in terms of farming, one needs less pressure or submerged in shallower water and you have dome with it’s top above the water.
And people going into it, might require a pressure suit to breathe.
Now one would tend to want or favor fresh clean water but in terms of using water for pressure, if water is not very good, but there a lot it and cheap to pump, one use poor water.
And a lot water is also going needed if using nuclear energy.
A canyon might be easier to span than a crater, depending on the size of either.
Now, not thinking you have to have dome over the lake, but one could have dome and purpose dome is to reduce evaporation loss and allow enough pressure to so the lake water can warmer and not boil.
What pressure/temperature would water boil at on Mars? And how fast would water evaporate, would it be catastrophically fast?
I don’t know how they arrived at the conclusion about CO2. Earth’s atmospheric pressure is 101,300 Pa, while Mars’ is 636 Pa. But Mars’ gravity is 0.376 that of Earth. So the amount of atmospheric mass per square meter (101,300 Nt/9.86 m/s^2) on Earth is 10,330 kg/m^2, while that on Mars is 636 Nt/(0.376*9.86 m/s^2) = 172.5 kg/m^2. Earth’s atmosphere is 0.04% CO2, or 6.3 kg/m^2. Mars’ atmosphere is 95.97% CO2, so it has 167.3 kg/m^2, or 26.5 times as much as Earth, over every square meter. Even though Mars has only 25.4% of the surface area of Earth, it still has 6.7 times more total CO2 in the atmosphere as Earth.
The problem isn’t that there isn’t enough CO2, which even the warmmongers know is not the primary greenhouse gas. It’s that there isn’t enough (or any) water vapor. Water vapor has far wider absorption bands that CO2, and there is 10,000 times more of it in the atmosphere on Earth than there is CO2. Actually, there probably isn’t enough nitrogen or other non-IR absorbing gases. When an H2O or CO2 molecule absorbs an IR photon in the Earth’s atmosphere, it almost immediately transfers that energy to either a nitrogen or oxygen molecule, or an argon atom, by collision. None of the latter three emit IR. The effect is simply to raise the temperature.
Planetary engineering of Mars will take getting a lot of water there. Apparently, a subsurface liquid lake has been discovered, though that is in dispute. There is plenty of water orbiting Saturn. I think there are some clever ways that it could be transported to Mars.
What about the glaciers on Mars?
https://en.m.wikipedia.org/wiki/Glaciers_on_Mars
Also Jupiter, which is closer, but has a much more harsh radiation environment.
I was thinking of scooping up ice from the outer rings of Saturn, then accelerating it to a high enough velocity to reach Mars. The outer rings orbit at 17 km/sec, so escape velocity requires only 7 km/sec delta V. That’s only about 4.61 eV/molecule. Let’s say you actually impart 10 eV to each molecule. A 1000 MW electric nuclear power plant would allow you to accelerate 93.4 kg of water to a speed able to reach Mars every second. Actually, you’d only get half of that, since you’d need to send half in the opposite direction to balance the thrust. But that’s still 4 million kg a day, or 1.5 billion kg/year. Not bad for a start.
Saturn escape does not get you to Mars.
Jupiter has hundreds of thousands of icy rocks in L-4 & 5. Send them to Jupiter, gravity assist them to Mars – hohmann planetary transfer, areo-capture at Mars to high orbit of Mars.
Or impact them.
–What pressure/temperature would water boil at on Mars? —
Wiki says:
“The atmospheric pressure on the Martian surface averages 600 pascals (0.087 psi; 6.0 mbar),” And ” It ranges from a low of 30 pascals (0.0044 psi; 0.30 mbar) on Olympus Mons’s peak to over 1,155 pascals (0.1675 psi; 11.55 mbar) in the depths of Hellas Planitia.”
And a chart boiling point of water at lower pressure
https://www.engineeringtoolbox.com/water-evacuation-pressure-temperature-d_1686.html
0.088 psi water boils at 0 C
0.147 psi 7 C
So, large areas of Mars are at 6.0 mbar or less and you can’t have liquid water at such low pressures- it’s like CO2 on Earth it’s either solid or gas, Hellas Planitia is pretty large region [you put a couple States of California in it] and it could liquid water because it has higher air pressure. But there are also other regions which are not as deep which also have enough pressure [because they are at lower elevations] to liquid water which at a low temperature.
Maybe one will have settlements in Hellas Basin, but I tend to think it’s as likely or more likely to have towns near equatorial regions.[or tropics of Mars].
-And how fast would water evaporate, would it be catastrophically fast?-
Well, wind might cause Mars lake evaporate “catastrophically fast” by which I mean an hour strong wind could cause liquid lake to freeze. I don’t think Martian wind would cause much waves, but wind causing waves on a lake would seem to cause a lot of evaporation.
Having open lakes is based upon idea that water was pretty cheap- say 100 times more than cost water on Earth. If water more expense one could keep lake surface frozen and or other things to reduce evaporation.
But generally a large lake and it’s evaporation will have localized “environmental effect” which should reduce evaporation- but then again, maybe it will cause tornadoes or have some other very bad weather effect.
But roughly the water should be colder than the ground in daytime and warmer than ground at night- which basically a greenhouse effect. And if have lots of lakes, more greenhouse effect.and air in large region should be less dry.
And if believe in GHE theory [I consider myself a lukerwarmer] then you believe water vapor is the most dominate greenhouse gas on Earth. So I think the water vapor would be slight warming effect.
Or tropics of Mars has average temperature of about -50 C, and having **a lot** of lakes could warm average to -20 C, and radiant effect of H2O gas might add 5 K, so increasing Mars tropics average temperature to about -15 to -20 C.
Which I regard as is minor improvement. It is more side effect and I don’t think Mars average or region average temperature is very important.
But could get a dome covering a body of water which holds 1 psi pressure [or less] and one do that on the moon also.
With fresh water the highest density is about 4 C, or water colder than 4 C rises, which could work on Mars.
But if have lots of saltwater or other impurity, one use something along lines of solar ponds, which allows warmer salty water to be denser than less salty surface water, though that could have more”catastrophical” problems related to wind- assuming Maritain wind could mix the surface waters.