How could we and would we terra-form the moon? I mean, theoretically speaking it should be possible and not too much of a challenge. But i don't know a lot of things, so i'm just not sure.

I came up with several ideas, most of which are out there and some i think to just not be possible.

Idea 1(The Probably Not Possible Idea): Could we potentially terra-form the moon by somehow plopping down like 50,000 to 100,000 trees at the same time?

Idea 2: Perhaps we could put a gigantic dome on the moon that completely covers it, but just more than likely is perhaps the size of a small city or large town. Then using technology we could potentially terra-form the inside, i'm not super smart and need to educate myself more so i'm not so sure about how to do or explain this better.

Idea 3: Maybe use an artificial gravity generator of some kind along with an extremely large water making machine and some trees (All of this is super futuristic stuff) would that be able to terra-form the moon?

I really don't know too much about anything, though i would like an answer to this question and some theories from you all as to how we could get it done. Plus it would be pretty nice to know if we could, after terra-forming it, potentially live on the moon with a small to moderate scale society. Perhaps a short stop area before going to mars or something.


Phase 1 involves putting a roof on this moon cave (and others like it), and cleaning out the dust from inside these future habitats.

For Phase 2, drop an army of robots on the surface and have them scavenge raw materials (carbon dioxide, water, metals and trace minerals) to stockpile in the roofed caves.

Once adequate raw materials are present, Phase 3 will involve shipping in fungi algae and any missing soil nutrients to start building a self sustaining oxygen-rich atmosphere inside the roofed caves. Mirrors can be added to the roof to provide some interior light during the lunar days, while solar panel supported batteries can power artificial light and heat sources when necessary.

As conditions improve inside the cave, higher plants, micro organisms, worms and eventually insects can be added. Genetic engineering should give us substantial help at this stage as lifeforms can be shaped to meet our growing environment's specific needs.

Throughout this time, mining robots will be expanding the caves, creating more shielded real estate while liberating useful raw materials from the excavated soil. Item by item, the fundamental needs of a self-sufficient environment can be identified and met. Those which cannot currently be met using local (lunar) resources can initially be shipped up from Earth, but always with a goal of developing a method for self replenishment.

Somewhere along the way, the focus of the plant life will shift to include food production as well as soil/atmosphere development. Eventually, the self sufficient islands of life will become strong enough to host an occasional human visitor. ...later still, a permanent human settlement.

From there, it is just a matter of rinse and repeat. Find/build more caves, add roofs, develop the soil and atmosphere, then move humans (and livestock) in. Once there are a hundred living caves, we will have a secure hold on our second biosphere. Once there are a million caves, then the moon is ours forever!

...and with the techniques we've learned along the way, all the caves in our solar system will someday host human life.

  • $\begingroup$ Don't forget the occasional internal airlocks between hermetically sealed parts of the caves, otherwise a single meteor impact or botched landing attempt would depressurize the whole colony. $\endgroup$ – vsz Dec 1 '18 at 18:36
  • $\begingroup$ Fungi use oxygen rather than producing it. To get oxygen you need a photosynthetic organism and light energy. There's no way around the energy requirement as the aim of photosynthesis is to achieve CO₂ + H₂O → O₂ + carbohydrate, and those products have higher Gibbs energy than the reactants. $\endgroup$ – GKFX Dec 1 '18 at 20:14
  • $\begingroup$ @GKFX, thanks for keeping me honest. So instead of fungi, phase 3 should involve algae or genetically enhanced simple plants which can somehow endure the hardships of lunar cave life. As for energy, we should be okay on that issue. The moon gets as much if not more energy per square foot than the Earth's surface (during its' days), and funneling it into the caves is a comparatively small engineering challenge. $\endgroup$ – Henry Taylor Dec 1 '18 at 23:30

Option 1

Maybe feasible : terraforming the moon with an atmosphere. I see a problem with radiation shielding, even with a lovely atmosphere.

Option 2

Makes a lot of sense, at far less risk and cost.

Various approaches have been proposed to simulate Earth gravity, likley optimal to human health, longevity.

Least Exotic - Tilting Train :

enter image description here

"One method of augmenting gravity is a extraterrestrial railroad. A vehicle on a circular track banked with respect to the horizon creates centripetal accelerations related to the speed of the vehicle and the diameter of the track. Incremental accentuation of gravity may be accomplished by switching the vehicle to a track of larger diameter and steeper bank. Rotation creates accelerations on the vestibular canals of the inner ear that will limit the angular velocity of the vehicle. Colonists would have the opportunity to work part of each day in simulated Earth gravity and easily access the planet's surface. The magnitude of gravity that will protect us is unknown, as is the frequency and duration of exposure. This must be investigated. An extraterrestrial railroad, as one solution to this problem, does not involve exotic technology and is readily expanded."

More Exotic - Centrifuge : enter image description here

Program, Challenges

Perfect, with a small-scale community, a sustainable biosphere (sub-surface, replicable, scalable) given importation of essential minerals, water, carbon, etc. needed to get things underway. Then scale out.

Not sure about the sustainability long-term, regarding water, metals, carbon & energy sources, however, given near-term technology. That doesn't need to inhibit making a start, even step-wise. This might imply a critical-path thru comet & asteroid mining to get things completely free of Terran dependencies.


  • The first small but significant benefit of this capability, when mature & self-sustaining, is an added biome redundancy in the event of planetary debacle of some sort, which we know to occur occasionally, some of which threaten to be catastrophic in the extreme.

  • The second, the basic engineering infrastructure of terraforming will have been proven.

  • The third, a space-launch capability for much larger craft can be based on Luna. It would likely also be the hub for space-mining craft manufacture/maintenance & materials processing.

This is in my opinion the obvious first step to any Martian terraforming project - work out the basics on the moon. And I bet that's how it'll happen, when it gets underway hopefully before not all of us to old to see it take shape.

Luna, not Mars, is our natural test bed.

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    $\begingroup$ Luna may be closer, but it's magnitudes harder to terraform: Afaik, no plant will survive alternating two weeks of scorching sun and two weeks of night. Mars rotates at a similar speed to earth, so shadow-loving plants will grow fine there without extra illumination and light shielding. For Luna, you'll need to pass half the sunlight through some technology before you can feed it to your plants... $\endgroup$ – cmaster Dec 1 '18 at 11:49
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    $\begingroup$ Its a LOT closer. this scenario is under a dome, likely primarily underground. the light cycle, entire climate, should be artificial. $\endgroup$ – theRiley Dec 1 '18 at 11:51
  • $\begingroup$ Actually, no. According to Wikipedia (en.wikipedia.org/wiki/…), you need about 15.7 km/s delta-v to get to Luna, and about 19.5 km/s to get to Mars. The later figure may be reduced significantly by aerobraking (directly hitting Mars' athmosphere instead of firing rockets to decelerate), so it's round about even between these two trips. Yes, you do a lot more kilometers on the earth-mars transfer, but those kilometers are irrelevant for the costs of the trip. $\endgroup$ – cmaster Dec 1 '18 at 13:19
  • $\begingroup$ interesting. yes, 200-fold avg. distance difference moon & mars. what about time ? and those figures are probably only appropriate at mars closest approach, yes? $\endgroup$ – theRiley Dec 1 '18 at 13:22
  • $\begingroup$ @cmaster That is not entirely true. You have a point and in fact I probably would have made the same comment if you had not been faster but you are missing the life support issue. Travel time does change and that does impact the mass you need to apply that delta-V to, which does make a big difference. There are actually ways to reduce this by essentially building transfer infrastructure between the orbits but that won't help with the cost of the first colony. $\endgroup$ – Ville Niemi Dec 1 '18 at 13:33

Squeeze it, as described in Wil McCarthy’s novel To Crush the Moon. If you can make it dense enough (with technology that’s indistinguishable from magic), you can still have a pretty useful surface area and also 1G of gravity, so that it can hold on to an atmosphere indefinitely and be healthier for humans to live on it.

  • $\begingroup$ Density & mass aren't the same thing, a smaller denser moon will weigh the same as the original moon, unless you add material to it, same weight same gravity surely, you need to elaborate the answer somewhat perhaps. $\endgroup$ – Pelinore Dec 1 '18 at 23:40
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    $\begingroup$ @Pelinore The mass will be the same, but the surface gravity will be higher, because the surface will be much closer to the centre. Why do you think that Neptune, Saturn and Uranus, which are all very much more massive than the Earth, have pretty much the same “surface” (really cloud-top) gravity as the Earth does? $\endgroup$ – Mike Scott Dec 2 '18 at 9:21
  • $\begingroup$ I was hoping to prod you into expanding your answer rather than adding a comment :p : gravity weakens with distance so if all a planets mass is closer together (denser) you'll be closer to more of its mass at the same time while standing on its surface so its gravity is stronger (or something like that) I'll have a look for the formula later when the cat gets off my lap. $\endgroup$ – Pelinore Dec 2 '18 at 10:41
  • $\begingroup$ @Pelinore The full version of my answer is the referenced novel, which wouldn’t fit here. $\endgroup$ – Mike Scott Dec 2 '18 at 11:26
  • $\begingroup$ Of course it would fit : the formula for calculating a planets gravity, the calculation for the moon as is & then the calculation for the moon when dense enough to provide 1g together with maybe it's new surface area ~ it could probably be expressed in almost as few characters as in this comment, well with a few lines of text to explain them maybe twice the number :) $\endgroup$ – Pelinore Dec 2 '18 at 11:39

How would we terraform the moon?

We wouldn't, at least not in the way that "terraform" usually implies.

One of the biggest issues with trying to terraform Luna is the composition of the lunar regolith. Chemically speaking there is plenty of oxygen, silicon, and iron available but other vital things like carbon and nitrogen appear there much too rarely to support carbon-based crops, or support our 80/20 nitrogen-to-oxygen breathing preferences. This basically means that whatever carbon we need for crops/food will need to be shipped in (ideally without depleting Earth) along with all the nitrogen we need to properly balance our atmospheric breathing gas mixtures.

The sheer volume scale for the amount of nitrogen and carbon needed to get a basic atmosphere started globally would be ridiculously extreme as an upfront investment. Lunar pioneers would find it far more cost effective to make small contained volumes very habitable for development, rather than to make the entire inhospitible volume imperceptibly more habitable. Basically, if they harvest a C-type asteroid for all the carbon/nitrogen it's worth, and bottle it all up in an airlocked dome where they can grow crops and breathe, then they can live and prosper in their mini-world while investing further resources toward more expansion and development as they harvest more C-type asteroids. (Compared to the un-domed terraform plan which would require mining hundreds to thousands of similar asteroids, and still have the atmosphere feel like an airlock that is 99.9% evacuated.)

Basically, you're looking at something similar to your Idea-2 plan, but put together very piece-meal over long time periods rather than ever being a single large investment.


Other answers outline the key points of using robots and harvesting light with plants and solar panels, but one interesting technology is "Solar Foods" (https://solarfoods.fi/). Photosynthesis has significant inefficiencies and also requires – for all known plants at least – a vaguely Earth-like atmosphere. It's been suggested by this firm that you could create foodstuffs without agriculture at all, supplying the needed energy by electricity to go from CO₂ + water to a foodstuff. (They have a few photos of protein they've produced on their site though it's not clear how fast they can produce it as yet. They're targeting commercial production in 2020 so I guess we'll soon find out!)

Covering the moon in solar panels for electricity and then generating food from that might be substantially easier as solar panels can survive in a vacuum. Of course, favourable conditions would be required in the manufacturing area, but this could be substantially smaller than the equivalent farmland.


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