Lunar biomes

terraformed moon.png

See this map, this is the go to map for most people looking for a map of a terraformed moon. This is probably not the most accurate map out there, but that's not important, what is important is our intentions. What I hope to accomplish with this thread is to create a "realistic" biome map of the Moon.
So, anybody want to join in?
Why wouldn't it be cool desert mixed with occasional dollups of heavily regulated forest?
I was thinking it would mainly be grasslands of varying dryness, with a mid sized desert in the west, and some sporadic forests and marshland around the more lake filled regions.
Then of course there's a matter of mountains, hills, or other things which might obstruct rain and clouds.
First, we need to decide how well and how thoroughly the moon has been terraformed. Is the atmosphere at 1 bar, or 0.1 bar? Is there enough oxygen? How much water is on the moon?

Then, related, we need to decide if the moon has been "spun up" or not. Climate on a world with a 24 hour day is much different than a world with a 708 hour day. Note that the moon doesn't have to be spun up literally; we could deploy enormous mirrors and sun shades to artificially project night and day cycles in any way we want.

Atmospheric cells will be very different here in any case. The atmosphere on the moon will be much "taller" due to the low gravity and the circulation faster due to the smaller size.
First, we need to decide how well and how thoroughly the moon has been terraformed. Is the atmosphere at 1 bar, or 0.1 bar? Is there enough oxygen? How much water is on the moon?

Then, related, we need to decide if the moon has been "spun up" or not. Climate on a world with a 24 hour day is much different than a world with a 708 hour day. Note that the moon doesn't have to be spun up literally; we could deploy enormous mirrors and sun shades to artificially project night and day cycles in any way we want.

Atmospheric cells will be very different here in any case. The atmosphere on the moon will be much "taller" due to the low gravity and the circulation faster due to the smaller size.
According to this (rather starry eyed) article the Moon would be Space Florida. Though no one seems to have been able to solve the "the moon has no radiation protection" issue yet.
According to this (rather starry eyed) article the Moon would be Space Florida. Though no one seems to have been able to solve the "the moon has no radiation protection" issue yet.
VERY interesting! As a native Floridian, I'm not sure Space Florida is a good thing, but as long as we don't import alligators and meth-heads things will be OK.

Even the poles will still be pretty warm due to the short trips the convecting air will need to make to get there. But the day/night cycles at the poles will be very odd. The permanently shadowed craters will be illuminated not by the sun, but by a perpetual blue sky, with the sun hiding behind the crater rims. These polar craters might be some of the best tourist spots! Slightly cooler, and without the sun's constant glare (again, growing up in the Sunshine State taught me to hate the sun).

As for the "no radiation protection" issue, a colleague of mine wrote this paper on an artificial magnetic shield to protect Earth from solar flares. (click the PDF link on the right of the page to read it) This proposal would need to be changed significantly to let it protect the moon, but it would certainly be possible for any civilization already dropping 100 Halley-sized comets on the moon!
VERY interesting! As a native Floridian, I'm not sure Space Florida is a good thing, but as long as we don't import alligators and meth-heads things will be OK.

Even the poles will still be pretty warm due to the short trips the convecting air will need to make to get there. But the day/night cycles at the poles will be very odd. The permanently shadowed craters will be illuminated not by the sun, but by a perpetual blue sky, with the sun hiding behind the crater rims. These polar craters might be some of the best tourist spots! Slightly cooler, and without the sun's constant glare (again, growing up in the Sunshine State taught me to hate the sun).

As for the "no radiation protection" issue, a colleague of mine wrote this paper on an artificial magnetic shield to protect Earth from solar flares. (click the PDF link on the right of the page to read it) This proposal would need to be changed significantly to let it protect the moon, but it would certainly be possible for any civilization already dropping 100 Halley-sized comets on the moon!
The thing about terraforming is that its doable (arguably) with today's tech. It's just getting everyone on the same page. If the world got together and pooled resources we could start r&d today.
The thing about terraforming is that its doable (arguably) with today's tech. It's just getting everyone on the same page. If the world got together and pooled resources we could start r&d today.
I tentatively agree. We have the technology, but we are somewhat lacking in the science and engineering aspects.

We're halfway there scientifically, but we need more robust climate models which are both extremely accurate and locally detailed. It would behoove us to do all the science we can on the moon (learning its geology and history) before we start messing with it. We want to learn the consequences of our actions, and we want the pure science the moon can give us.

We have the technology to do this, but the application of that technology in the exotic environments we will face will prove to be a fun challenge. We built nuclear-powered rockets in the 1960's, and we have landed probes on comets, but landing a nuclear engine on a comet and using it to direct the comet into the moon is another matter. Plus, the Russians just catastrophically lost a nuclear scramjet, so the engineering expertise there is dubious at best.

Finally, we need some awesome space infrastructure to support all this. That is a huge engineering and financial investment. Doing so will open up so much of the solar system for colonization and industrialization that it will be worth it, of course, but it will take some time.

How much time? I certainly hope I will see much of it in my lifetime. Same for terraforming and colonizing Mars.
Though no one seems to have been able to solve the "the moon has no radiation protection" issue yet.
Umm, wait. If the surface level pressure is in fact a full atmosphere, or even lower but at a level humans can adapt to--so at least half an atmosphere and probably more than that--as @rexnerdorum notes, the atmosphere is 6 times thicker than Earth's. That is, it is just as dense at the surface, but the scale height is six times greater. One has to go to six times the altitude one does on Earth to see the pressure fall to a given level.

Therefore the sheer mass of air between you on the surface and any sort of radiation in space is going to attrit every kind of radiation. And what Earth's magnetic field protects us from is Solar charged particles (has to be charged, neutral particles don't care about magnetic fields). The behavior of charged and neutral particles in a medium is fundamentally different; neutral particles (photons like X and gamma rays, neutrons, complete atoms but those would be stripped of electrons coming in at high speed and become charged) have exponential absorption and scattering and so some of it always gets through though attenuated--but charged particles strongly interact with the medium due to electromagnetic effects, producing secondary photon radiation ("Brehmstrallung;" it's how we make X-rays in vacuum tubes) and being strongly braked. The force is highest at higher speeds but the relation between acceleration and speed is such that the particle is braked to a complete stop at a finite, certain distance of penetration and beyond that thickness the radiation is zero, except for the Brehmstrallung secondary radiation filtering down. But nothing but air protects us from solar X-rays and gammas, the magnetic field does zero to affect those, so presumably despite the extra dose of it due to braking the charged solar wind particles the surface has lower incidence of that than we do here on Earth.

Whether solar particles get to the Lunar surface with zero magnetic shielding depends on their exact energy, but I would observe the auroras we get on Earth are caused by the solar wind flux being "grounded" as it were by the magnetic field configuration at the magnetic poles. It could be that their velocity is significantly braked before they drift to the poles, but I rather suspect the energy is mainly conserved in a thermalized plasma in the Van Allen belts, so they have similar magnitude of energy. And behold, the auroras do not touch the surface, they happen many tens of kilometers above the polar surfaces where the air is extremely thin.

So raw solar wind, and even relatively heavy waves of solar storm emissions, will beat down directly on the Moon--where they meet the atmosphere, and at an altitude six times higher than the auroras are on Earth, get braked to a dead stop. Sunlight, solar hard photon radiation, and cosmic rays (which are charged) will all be more attenuated than they are on Earth's surface.

Also, it is known that Earth's magnetic field is not constant but rises and falls in waves, reversing itself twice for a complete cycle, I forget the time scale of the cycle, but I gather we are experiencing measurable weakening of it now meaning we are headed for a minimum, at which point it might not be zero quite due to higher order complexities in the detailed pattern of behavior, but much lower, and must go through a net zero (perhaps with lots of local anomalies) before it comes back because it will come back with reversed polarity. We know this from signatures in rock formed by sea floor spreading, which produces bands of alternating polarity magnetized crystals.

So, we on Earth, anyway our ancestors, have lived through periods when Earth had essentially zero magnetic field and the charged stuff barreled straight on in as above to Luna, only the air layer is 1/6 as thick. It may be that animals and plants did suffer a bit from the radiation that got through, but hardly enough to arrest the circle of life; generations were born, matured and died without any strong indication of general ecological distress.

Overall then, I think the whole radiation thing is a big red herring; the atmosphere is plenty of protection all by itself. Over long time periods the atmosphere will evaporate away without some process of renewal or ASB ruling. Also, in theory the OP doesn't specify "the surface is Earthlike because sufficient mass of air exists to produce a full atmospheric Bar of pressure naturally under gravity;" conceivably there is an ASB force field holding in a full atmosphere pressure just a kilometer or two above the surface, or a glass ceiling held up with lots of pillars, or something like that. But the default assumption that there is simply enough air to produce the needed surface pressure indicates we can ignore the whole radiation from space issue.
The thing about terraforming is that its doable (arguably) with today's tech. It's just getting everyone on the same page. If the world got together and pooled resources we could start r&d today.
Well, sure, in some sense this is true. But not in the sense that we could do it with a moderate diversion of currently available productive capacity! We'd have to have some kind of gun to our heads like an ASB announcement that Earth will vanish in say 50 or 100 years, one that will be credible (and I have seen ASB threads like that).

If you do the math of how much mass of air one has to dump on the Moon to make the surface pressure equal to Terran sea level, for instance, it turns out to be a very large fraction of the mass of Earth's own atmosphere--so if an ASB opened up a magic portal between some point on Earth and the lunar surface, supplying the necessary potential energy difference to make it a simple matter of stepping through the door with no jumps of potential blocking the way, by the time the initial vortex of Earth atmosphere pouring out the door dumping atmosphere on to the lunar surface stabilized, with pressure matching on both sides, the surface pressure on Earth would be quite a lot lower.

That is a hell of a lot of nitrogen and oxygen and trace gases to scrape up out of the asteroids or whatnot and dump on the Lunar surface--also, we can't just drop packets because that would heat the surface--to be sure it would cool down to equilibrium eventually. But it is a really massive project all the same, one can doubt there are enough volatiles in the entire asteroid belt too. So what are we gonna do, boost the material up from Earth? Go out to Saturn and mine the ring ice?

It is doable in the sense that we can envision straightforward engineering solutions, but a lot less so in the sense of sane economics.

I'd prefer a straight ASB scenario--we wake up one morning and the Moon is a lot brighter because some ASB has done the terraforming for us overnight.

I think by the time humans are capable of doing this for a fraction of our total industrial capability small enough to pencil it in, we will have unguessed at capabilities and the point of Terraforming Luna will be moot. We could do it as a vanity project, but against that some people are likely to say "leave Luna pristine!" By then Luna will be much messed up by casual human activity of course, but the case for letting it alone on sentimental grounds might still be strong. Barring such an ASB thing as being given a countdown to Earth vanishing softly and silently away in 100 years minus and counting, we will never be in a position where we absolutely must Terraform Luna.

There are other practical problems that make it a big project not mentioned much yet. The chemistry of the regolith surface is all wrong for Terran ecosystems for instance, we have to remediate the soil a whole lot. I have yet to read Benford's essay and he might address some of these things, but again I like it mainly as an ASB gift, not as a serious FH project.
I'm glancing through Benford's article now. I can respect Benford; he's an SF author with a serious science background and ought to be trustworthy. But I am already coming on a bunch of howlers.

For instance, we really want it to be the case that Luna is tolerably habitable with just giving it an atmosphere and remediating the soil, without changing its spin even a little bit. The tidal pull of Luna on Earth is pretty significant of course, but Earth has over 80 times Luna's mass; the reciprocal tide of Earth on the Moon is thus 80 times as strong, and if it were to turn at any significant rate as seen from Earth, the tidal disruption of the shifting field on the Lunar surface would be catastrophic. If it turned relative to Earth in 80 days, the magnitude of the shift would be the same rate as we experience here...but Earth has been thus affected all through its history, and equilibrium takes that into account. Luna's layers would be experiencing this novelly and it might be millions of years before it stabilizes. Also Luna is frozen solid, with only a small layer of fluid core, and the rigid thick crust will respond to tidal shifts in a chaotic way, not smoothly. Meanwhile that slow turn corresponds to only a slight reduction in its day-night cycle. To spin it up to mitigate serious day-night thermal cycling or the winds necessary to maintain a moderate temperature difference, as the cases may be, will subject the surface to really massive tides. Again if we had an ASB scenario the ASBs might magically counter the tidal force somehow, but absolutely nothing in known human science as of this date will do that short of moving the Moon away from Earth--which to put it mildly is a massive project that will also affect Earth life adversely, and negate much of the advantage of a colony world currently just a light-second away, three days by currently attainable space travel tech.

So Benford remarking that impacting the Moon with comets is desirable to spin the Moon up is a huge flashing red light against his credibility.
...The tidal pull of Luna on Earth is pretty significant of course, but Earth has over 80 times Luna's mass; the reciprocal tide of Earth on the Moon is thus 80 times as strong, and if it were to turn at any significant rate as seen from Earth, the tidal disruption of the shifting field on the Lunar surface would be catastrophic....
Easily fixed with a sunshade and mirrors. Uh, well, not "easily" but it would be possible. Deploy a sunshade to completely block the light from the sun on the moon. Could be put in a funky orbit in the Sun-Earth L1 point, and it could use the light from the sun to push itself into position continuously, allowing its shadow to follow the moon.

Surround the moon with orbital mirrors in a nearly contiguous cloud, almost like a Dyson Swarm. Use more mirrors (or perhaps the sunshade) to focus light on these mirrors. Pay a grad student to do the trig and calculate the angles and positions of each mirror to simulate a 24 hour day on the moon.

Interestingly, if done right, we could direct the mirrors in such a way as to give everyone on the moon, regardless of longitude, a sunrise at about the same time. A noon at about the same time. And a sunset at about the same time. We could have 14 hour days and 10 hour nights if we want. Comparatively cool and warm areas could be made just by redirecting mirrors towards or away.

Assume it would take 3x the surface area of the moon in mirrors to do this. We can make 5 micron thick solar sails, so we can estimate a total mass of mirrors of 512 billion kg. Round that up to an even trillion to include the apparatuses to move the mirrors.

Total energy required to move a billion tons (1 trillion kg) from the lunar surface to lunar orbit - 2.83x10^18 J (presuming the stuff is manufactured on the moon, and that the mirrors can use sunlight to reposition their orbits, as we are trying now in real life).
Total energy required to spin the moon up to a 24 hour day - 1.504x10^23 J (I think - please feel free to check my math. I did it on my phone).

It would take nearly a million times less energy to just deploy a bunch of mirrors rather than spin up the moon. Add to that the important and disastrous consequences outlined by @Shevek23 and the choice is clear.
There should of course be cave biomes, with fungi and colossal insects and ooze monsters. These can extend much deeper than on Earth, thanks to the low gravity.
I'd be most interested in Benford, or someone credible, doing the math on the climate of a Luna with its current day/night cycle--as remarked above, a system of soletta mirrors could mimic a faster cycle by shining light on the night side and shadowing the dayside periodically, or in alternating zones, of course. I dislike that because it is a highly artificial system subject to system failure--unlike the military induced mirrors-falling catastrophe on Ganymede in The Expanse (and I am not sure of the dynamics of that either--The Expanse often falls short of its touted ultra-hard SF reputation, pretty good versus the usual cheap knock off space opera or big budget fantasy like Star Wars or even Star Trek, I suppose, but still loads of handwaving going on; sometimes the authors know it and sometimes they seem ignorant of their howlers) "falling" mirrors probably will be braked to harmlessness by the atmosphere, but the point is it is a point of failure I'd like to believe is unnecessary.

Air can surely bring a lot of heat from the day side to the night side. The question is how much would roughly 3/8 the mass of Earth's atmosphere bring, bearing in mind as Benford correctly notes Coriolis force is negligible. How cold would the night side be in equilibrium? How hot would the day side be? And what sorts of winds would accompany this transport process? It all depends on the numbers here. If it is a matter of say 30 C temperatures surging up to maybe 35 or 40, people can prosper in the ambient ("like Florida!") and survive the surges with shelter, air conditioned or underground, plummeting to say Arctic temperatures on the night side--well people live in Alaska or Siberia, and if they can look forward to a Florida like summer two weeks long after enduring two weeks of Alaskan winter cold and dark, why not? But how stormy will the transition be?

If we have a serious temperature differential between day and night side, the night side will have a lopsided share of the total atmospheric mass. Basically, the day side surface heats up, and heat is lofted upward by convection, and this essentially expands the air column and lifts the stratospheric level up. Note that stratospheric conditions hold 6 times as high as on Earth, 60 km up instead of 10. The "stroke" of the "piston" of the expanding day side air is longer, and the heat capacity of expanding air is 6 times as great. This expansion raising the stratosphere creates a slope, as it were, dumping high atmospheric air onto the night side. Meanwhile the surface of the night side is cooling a lot, and air there contracts--this is not a mirror image of what happens on the day side because the cold air does not rise to mix into the air column above, the cooling is by conduction in a much thinner layer. So mainly it is a process of the day side expansion dumping more stratospheric air onto the night side, shifting mass from the day side to the night side. This process raises the pressure of the whole night side air column, and air being compressed warms up. We get equilibrium on the night side when the incoming air from the day side compresses the air on the night surface at a rate that exactly compensates for the cooling by conduction caused by the surface radiating heat into space. Because black body radiation per the Stefan-Boltzmann law has power varying by the fourth power of the temperature, a modest reduction in temperature at the surface results in a sharp reduction of infrared output to space, so fairly modest heat transport by the atmosphere can suffice to maintain a dark side equilibrium way warmer than the current lower temperatures the night side in vacuum reaches.

The complete cycle in equilibrium takes into account how the pressure differential between the hemispheres changes with altitude. As noted, heating the day side elevates the upper atmosphere by expanding the lower atmosphere, and in terms of pressure differentials this means at high altitude, day side air is at higher pressure at a given (high) altitude, thus driving upper atmosphere flow to the night side. But I have noted this process shifts the total air mass from the day side toward the night side--in equilibrium, the night side surface pressure is higher, because more mass of air lies above every unit area on the surface. Therefore at surface level, the flow is reversed--cold dense surface air seeps back to the day side at surface level, and the cycle is closed, a conveyor that shunts chilled night side air past the terminator to balance the air flow above the terminator at high altitude into the night side upper atmosphere. The two hemispheres reach a balance, where the day side air mass is thinner and the night side air mass is thicker--maybe not so much geometrically because the warmer day side air is less dense and the cold night air is denser. But mass is shifted to the cold side, definitely.

Wind speeds in the upper atmosphere are of interest to aircraft and spaceships and govern weather, but what we need to know for basic habitability is, how powerful are they at the surface? Note that the wind speed in the thin upper air must be a lot faster than on the surface for mass flows to balance, so when someone mentions wind speed we need to know which flow they are talking about. We can have them be a hundred mph and more up high and not worry, that is not untypical of Earth; we can't have a constant hurricane of cold night side air pouring past the terminator blowing that fast!

I haven't discussed "greenhouse effect" at all. Benford is surely correct in general that with six times the specific mass of air over any unit of surface (give or take day/night fluctuations) the thermal ballasting of the air will be greater. But humidity is pretty critical here! Water vapor in the air is a major part of what gives Earth its overall empirical greenhouse levels. And in fact while I simplified the basic climate model to have all heat radiate from the surface straight into space, it is much more complicated than that; Earth's black body temperature as measured by infrared instruments in space is a lot lower than the surface averages around 285 K or so. A better model is to say we have a layer in dynamic equilibrium lofting heat up by convection from the warm surface to a cooler upper layer where the radiation actually comes from at a cooler temperature. But alas even that is not nuanced enough! In truth the heat balance of Earth's atmosphere is quite complicated. Some light is simply reflected away and has no effect on temperature (except by its absence). Some punches right through to the condensed liquid/solid surface and warms up stuff there directly. Some of that is reflected away there and does not heat the surface, and some of that bounced up light gets intercepted and absorbed on the way back out and some of it simply escapes in diffuse reflection. Some radiation is absorbed directly from sunlight coming in, some as noted by sunlight bouncing out. Some of the heat reradiated as black body radiation from the surface finds its way to space and departs, some is reabsorbed in the atmosphere. And meanwhile in addition to heat leaving the surface as IR radiation, another flow is into the air by contact, and the air has various modes of circulation. Expanding air absorbs heat, contracting air gets warmer and extrudes it.

And water is crucial to many of these processes, and complicates all of them. Clouds account for a great deal of Earth's reflectivity. Water vapor accounts for much of the direct absorption of heat from radiation going both ways. As air containing water vapor expands and cools, the vapor pressure of water drops which means a given quantity of water vapor reaches saturation and must condense, and as it condenses it releases latent heat which partially radiates away, and partially heats the air parcel and thus sustains its further expansion at a warmer temperature; the water must form droplets or ice crystals which form clouds and change the reflectivity of the air.

As it happens the OP map shows remarkably little surface water bodies! Furthermore, the basic relief of the Lunar and Terran surfaces, both stripped of all fluids, are quite different from each other. Luna's is essentially a single moderate slope from its highest peaks to its lowest points (measured in terms of geopotential--"selenopotential?" height above the body's center). Earth on the other hand has two distinct altitude zones of its crust--the baseline is the oceanic sea bed, basaltic, dense and thin, which is largely of a level but with some considerable variation, I believe already with relief with more scope than the Lunar surface. And about 3/10 of the whole area is covered instead with much thicker, less dense granitic continental rock towering some miles above the sea bed average elevation, with a fairly sharp slope between them. If we were to cover Luna with water so that it too had just a third of its surface poking out above the resulting average datum height, that would now be literally a new sea level, the mass ratio to that of Earth's oceans would be far lower than the area ratio of Luna to Earth (about 1/16) because these oceans would be much shallower. The map shows a reversed ratio or even less, a third, a quarter, a fifth of the planet's surface in water. These are relatively thin puddles versus Earth's oceans!

Now the depth does not matter so much for climate, provided it is deep enough that the bodies don't evaporate away completely. It is surface area under sunlight that provides atmospheric moisture.

On the other hand, as noted the air layers are six times as thick, so a given area in a given more or less steady state, some breeze blowing in air of a given humidity and temperature over water getting a given degree of solar heating, can pick up six times as much total mass of water before parameters are changed by this process.

Greenhouse properties therefore might be 6 times as strong at given humidity levels, so it might be desirable for the air to be rather arid versus Earth to prevent a runaway greenhouse heating spiral. Considering that the average temperature on Earth's surface is empirically cooler than Benford's "Florida" comparison, Benford seems to be counting on a little bit more greenhouse effect than Earth has, especially to warm up the night side. But it could well be the scanty water bodies shown are limited advisedly, precisely to prevent humidity from being so high that the place surges to much higher than 30 C in the day time.

Since Terran organisms have adapted to a 24 hour cycle, the "Dyson swarm" of artificial day/night producing mirrors might be quite necessary after all, if we agree spinning Luna up to a 24 hour day is a no go due to tidal issues. If we do that I suppose Benford is perhaps broadly and qualitatively correct, though I don't trust his breezy notions of affordability of these projects one little bit!

I mean, the comets are way the hell out there, beyond Neptune's orbit generally; we can't even realistically talk about a crewed mission to Saturn! We might with a suitably efficient and powered low thrust, high Isp constant thrust drive, preferably one that refuels with new reaction mass in situ at the destination--pointing toward wanting a simple reaction mass like hydrogen, water or methane. But a comet expedition? One that lassos a whole comet and diverts it to smash into Luna? OK, really we are going to use nuclear shaped charges and vaporize some of the comet mass for reaction mass. No matter how we do it, it is a huge project with huge expenses.

He couldn't resist the Helium 3 red herring either. I never understand why people say "oh, we have to mine Helium 3 from the Moon!" When tritium decays, it decays into helium 3--so if we can generate tritium, all we have to do to get an equal (well almost identical) mass of He3 is just wait for the decay. The half life is on the order of months I believe, and we know how to get tritium from lithium. So basically our planetary lithium supply is actually a helium-3 source and I doubt going to the Moon to get it in situ He-3 is more cost effective. So every time someone mentions helium-3 mining on the Moon, they lose major credibility points with me.

Not to mention we have yet to figure out how to practically actually fuse He-3 for the touted clean fusion reaction!

I enjoy talking about a Moon with an atmosphere, particularly if it has an established ecosystem. Even without any attempt to moderate its day-night cycle and thus facing some pretty severe climate variations over a month, I think it would be quite livable. No one yet is discussing the fun to be had in 1/6 G, humans flying around with Daedelus-Icarus style strap on wings and so forth. If the ASBs provided an ecosystem that had a few million years to evolve adaptations to the peculiar conditions, it ought to be pretty exciting, with loads of critters in flight. I'm tempted to describe a trip there using the SpaceX "Starship"/Super Heavy booster system. Note that nothing we have on the shelf right now can take humans there and return them, and if the ASBs had replaced the Moon with an atmosphere graced one during the Apollio program, we'd have been unable to meet JFK's deadline--oh, landing two or even all three astronauts on the Moon would be easy peasy, but "returning them safely to Earth" would be a whole nother problem. I daresay replacing the LEM with a thing that can aerobrake to a soft landing and then later blast the crew back into orbit to meet a waiting CSM is doable, but it would require, I think, at least a separate Saturn V launch--this assumes no reliance on in situ propellant; if we set up a Moon outpost with a fuel and LOX plant, it would be quite a different story.

Come to think of it, while a first expedition to the Moon cannot rely on in situ fuel, it would be much easier to produce the liquid oxygen required to boost back to LLO--it just takes power and some kit to compress air, and fraction out the LOX. And guess what, oxygen is far and away the biggest mass in an oxygen-fuel propellant mix! So perhaps landing with just the fuel needed to return to space, with some extra to power a LOX generator, can do the trick after all, with all up mass to land not a lot higher than the LEM's 15 tonnes?

Orbital speed is much lower than Earth orbital speed. OTL NASA budgeted something like 2200 m/sec delta V needed to reach the CSM parking orbit from the surface in the Ascent Module of the LM. Now because the full pressure surface air is a lot thicker than Earth's atmosphere, which already requires parking orbits to be some 200 km or more above the surface, so despite the lower orbital speed it might be close to a thousand km height orbit that has to be reached, the delta-V from surface to orbit will be higher, and rockets are less efficient in dense air. So these are drawbacks. OTOH, something like a jet turbine can give you serious thrust, against a far lower gravity, with much greater efficiency--why even bother to refine LOX out of the air, when you can just burn it mixed with nitrogen in a jet engine? As the craft climbs, the air will thin albeit slowly, and meanwhile it is hard to get efficient jet propulsion at supersonic speeds--the SR-71 scout plane could cruise at Mach 3.5 or so, which is about half the delta-V needed, so 1960s American technology could make a suitable jet engine, but it would be for a first stage as it were, something to ram them up halfway or so toward orbital transfer speed, but they'd need to switch to a rocket to get the rest of the way there. But that would be little problem I would think, they would save so much propellant requirement using airbreathing jet engines that they could afford to land the sheer mass of the dang engine and some auxiliary fuel for running a compressor for LOX for the upper stage. They could even use a jet engine suitable for blasting back to orbit to power a rotor not unlike the Fairey Rotodyne, so the lander would be a helicopter essentially.

It is a different design than OTL Apollo then, even sticking to the basic LOR concept; the CSM needs a lot less delta-V to go into a high Lunar orbit, while the lander/return thing is as much an aircraft as spaceship and needs to be heavier, and it might be necessary to do two launches, one to send the lander there and another to send an Apollo style CSM variation. But it might also perhaps fit in the OTL 45 tonne to Lunar encounter payload of the Saturn V!

To be sure, we'd want to seriously quarantine the astronauts after they come back to Earth; God knows what Lunar organisms might do in Earth's ecosystem!
I've been musing some more about an ATL Apollo per JFK's arbitrary "within the decade" deadline, and while I have done all the math in my head and not looked up hardware specs at all, I think it is possible to make a direct descent/ascent "Apollo" using ballistic atmospheric entry (capsule design, not spaceplane) at both ends, taking advantage of very well developed low-supersonic capable turbojet engines and a slightly risky (but seriously considered, in the 1960s) ramjet phase of some kind, segueing over to pure rocket thrust, to land and return the capsule with all three astronauts with no in situ attempts whatsoever, and all this can probably fit well within the 45 tonne throw weight of the Saturn V to a translunar trajectory. In other words, Armstrong, Aldrin and Collins can land on the Moon and return safely to Earth by mid-1969, using the same rocket and a quite different Apollo design, and unlike OTL we can be pretty sure this tech, or something incrementally improved on it, can be sustained for an ongoing Lunar exploration segueing into colonization program through the Seventies and beyond! This might well require larger NASA budgets to be sure, but the prize is ready to hand--an already habitable Moon of great scientific interest and considerable utility for pressing on to deeper space exploration.

A caveat I have mentioned and always harp on in habitable planet ATLs--if the Lunar ecology is even vaguely similar in biochemistry to Terran, the threat of serious biohazard to Earth is quite real. It would surely be necessary to decontaminate the returning craft before it reaches Earth to assure killing any little bugs or molds that might hitchhike, and keep initial exploration crews well sealed from bio-contamination, and sequester them on return with major, Andromeda Strain type heroic efforts. It might make a lot more sense to design the returning capsule to skip-brake off the Earth's atmosphere into LEO, and have a decon space station it docks with for the crew to first be taken off with elaborate decon efforts, and quarantined in orbit for a good long time to make sure some sneaky bug didn't get past these, and meanwhile have other crews very very carefully scour the ship and still keep it mothballed for years or decades of research on orbit, handle bio-samples deliberately taken like they were made of plutonium and do all the bio-investigation again in orbit. Then plan later expeditions without Kennedy's "return safely to Earth" being guaranteed, recruiting rather fanatical scientific and other gung ho types to basically commit to colonization, setting up a one-way Moonbase (essentially a frontier town) to be as self-sufficient as possible and serve as volunteer guinea pigs to see if they catch something Godawful (and perhaps all die) and postpone any plans to come home for years.

The nifty aspects of life in 1/6 G are offset by the semi-known medical risks of trying to live that way long term. It is only semi-known because we have extensive knowledge of variable gravity biology at just two throttle settings--1 G, and zero. We really don't know how humans or any of our animals, or plants, will react to being in 1/6 G for months and years. As a little side rant, we ought to know more about this by now, as one purpose of having LEO space stations would be to set up experiments in medium acceleration and research the heck out of it, but some kind of centrifugal environment is admittedly a costly investment and tricky, and everyone has put it off to manaña. So we don't know whether asking people to stay on the Moon for even say only a year is a death sentence, a life exile sentence (they adapt well enough to sustain a normal lifespan, or perhaps due to lowered strain actually live longer assuming they have Terran equivalent infrastructure, but irreversible adaptions mean they are doomed to be cripples with shortened life expectancy if they ever return to Earth) or if perhaps with good rehabilitation they can pretty much recover. Perhaps the latter will be true of people who come back within say a couple months but not those who stay more than a year.

What about reproduction? A lot of wiseacres have opined that fertilization and gestation is plainly impossible in free fall. Well, I would expect it is not possible for a woman to birth a viable baby gestated in free fall, perhaps, but the argument that OMG, gravity is ubiquitous on Earth and lots of processes assume it, seems much offset by noting that animals move around and this subjects their cells, including those of developing embryos, to all sorts of off axis accelerations. Does a female gibbon need to fatten herself up to live motionless while she develops her offspring, holding absolutely still, or use some kind of instinct in her mate to compel him to bring her food for half a year or however long gibbon gestation lasts? Nope, she keeps right on swinging around gymnastically through the branches, hurling herself into hundreds of (admittedly brief) free fall trajectories followed by high G arresting grabs daily, leaping away from predators and toward food opportunities all day long for all those weeks. So far as I know no mammal, or bird, or insect, has instinctive periods when some hormonal cue tells them "lie still and think of England, because you have embryos developing in a critical stage where the least shock will ruin their body plan being laid out!" Animals just have to be tolerant of unexpected as well as planned acceleration surges and that is that.

We can be more positive about it. I have lost track of the reference, but some years ago I learned there was a Russian experiment where they took some female cockroaches, which had been inseminated--but roaches often withhold and sustain semen and fertilize their eggs later; steps were taken to make sure these bugs had not in fact fertilized their eggs just yet I gather. They were launched into space on some free flying satellite (this was not an ISS experiment and it was uncrewed, except for these roaches of course). They were given time to inseminate the eggs but not to hatch them, and the craft was brought down, and the eggs extracted to be hatched. Note the mother females had gone through high thrust launch, at least 3 Gs and given the Russian rocket practices a lot higher, and similarly the developing eggs had gone through a high G reentry as well. But a substantial period of their development from initial fertilization to being nearly ready to hatch happened in free fall.

So they hatched the eggs, and lo and behold, from the description not only were the baby roaches viable, they appear to have gained Marvel Comics superpowers from their stint in space! Presumably not from radiation despite Marvel canon! They grew bigger, stronger, ran faster with quicker reflexes, this is what I recall reading!

(Practical moral...make damn sure your spaceships do not have unwanted unmonitored cockroaches hiding in the supplies or elsewhere, or their offspring will turn into a race of conquering superbugs!)

So maybe it is just roaches only, they being such pesky supersurvivalists already. Or insects and perhaps arthropods in general, but not mammals or birds?

Anyway free fall is not 1/6 G. I'd worry a lot about the ethics of a woman being impregnated in space, in free fall, or even on the Moon. There are all sorts of reasons to fear that development cannot proceed quite normally in such circumstances, or at any rate the poor baby is born with zero prospect of later adapting to live under a full G, and probably has serious medical issues even at 1/6 G. And developmental mishaps could doom a mother trying to bear such a child and mandate abortion as the only possible survival option for her.

We just don't know. And to rant again, we bloody well should know, if not for humans (God knows when we will dare to cross that horizon; Musk with his live on Mars ambitions should bloody well be thinking hard about it) then for mice and other experimental critters. But we really don't. The roach experiment gives me some optimism humans can adapt, at least one way. But we won't know until we try.
What I hope to accomplish with this thread is to create a "realistic" biome map of the Moon.
I have followed my own little muse which is enthusiastic about aeronautics and astronautics and space missions as soon as damn possible. The project here is biomes, which is why we are in the Map section I guess.

But I have remarked that perhaps, to keep the ambient temperature of Luna's daytime surface reasonable, we might actually want to minimize rather than maximize the greenhouse effect. Earth is certainly said to be in danger of runaway greenhouse effect. The way that works is, the amount of water vapor in the lower atmosphere depends to a great deal on the saturation humidity capacity of the air, which is strongly dependent on temperature. If the surface warms up significantly, more water can evaporate and be lofted up higher before the air parcel it is in cools enough to saturate and start releasing the vapor as condensed liquid or solid water--which forms clouds. Clouds reflect light but also absorb heat, as does water vapor in gas state. The more water, the more heat can be trapped, balanced perhaps by more clouds reflecting away more light. Combining that with a thicker atmosphere, that is six times as many cubic meters corresponding to six times the linear length at a given density range, and perhaps Lunar air humidity has to be kept rather low on the average to prevent a runaway greenhouse heating.

This might suggest that the average saturation of the lower atmosphere air must stay low, which implies pretty arid conditions on the surface--rather consistent with your map as it happens.

The effect on biomes is that broadly speaking, upwind from a given crater lake or small sea, the air is arid, and downwind the water that does evaporate will be diluted in lots of warm still fairly dry air. It has to precipitate somewhere to be sure!

Lo and behold--if the day side has very low precipitation, as air is lofted over to the night side it ought to cool and the water snows or hails out, and once fallen, if the surface temperatures drop below freezing, it largely stays put in drifts...until dawn comes and the surface starts to be warmed. Ice will melt and be liquid water at very low temperatures just a few degrees above freezing, and so might soak into the ground or be sequestered by organisms, plants tapping it out of the soil or animals drinking it. There might be a mad scramble in the ecosystem to sequester the water against the hot dry period of most of the near two week long day, with plants using stored water and atmospheric carbon dioxide along with minerals and other nutrients picked up during the brief period of some days where liquid water is in air cool enough yet not to absorb too much of it, to use the abundant day sunlight to synthesize food to sustain the plant during the long cold night. If nighttime temperatures are below freezing, some organisms like arctic frogs might allow themselves to be frozen and go into suspended animation, and jump start themselves with some triggered chemical reactions to melt the ice and use up stored nutrients to get active in the early dawn period to scramble for more water and food.

Now against this interesting idea of a dry dry arid daytime with plants and animals watered by night side snow, consider again the details of how air circulates. Say we have parcels of dry air over a large body of open water, being heated by the daytime sun. Dry air will tend to absorb water vapor, encouraging evaporation which will cool the sunlit surface. Then, the parcels will rise convectively, expanding as pressure drops and thus being cooled but also lowered in density. Even if only partially saturated with water vapor before convection lifts the parcel out of contact with the open water, as the parcels rise they will drop toward saturation; after this the dry adiabatic lapse rate is replaced by a wet adiabatic lapse rate, in which temperatures fall more slowly due to heat of vaporization being released as water condenses. This lofts the parcel up still higher. But eventually, long before the stratosphere is reached, clouds will form and precipitation will occur, over the day side. If the surface is hot enough, the precipitation will evaporate even before it hits the ground, but this will cool the layer that absorbs it--checking convection, or trapping convective air in an inversion.

Thus while the air initially picking up the water is lofted higher than ever due to releases of heat of vaporization, the water molecules themselves tend to be filtered out, dropping as precipitation to lower levels. At least some of the time, precipitation will reach the surface, and will be scattered far from its condensed surface pool sources.

If much water is trapped at a low level, when the Moon slowly rotates into night side conditions, recall I have argued the lower atmosphere tends to have a wind blowing from the cold dark side to the sunlit side. Such winds would tend to push the more saturated lower level layers back to the day side. But also, being quite chilled by the night side (I haven't worked out how cold the night side might be to be sure) we have basically a warm front over an advancing cold front. Clouds will form there, heat of vaporization be released, lofting the air parcels and causing precipitation along the cold front--which tends, on the evening terminator, to fall through the very chilly intruding cold front air and either be frozen as sleet before it hits, or fall as chilled liquid but quickly be frozen on the surface.

In the morning, surfaces that have cold soaked all night are being brought back into the day side, along with a flow of cold dry air running ahead of the planetary rotation to again form even more intrusive cold fronts under a warm saturated front--again causing storms and precipitation, but this time even if it does fall in frozen form, the rising sun tends to warm the surface and melt any ice.

So it is a little like the model I first offered--the water vapor evaporating over the course of the day from the small seas and lakes and ponds might precipitate down during the day or might be trapped up higher, but still in the lower troposphere atop inversions. At sunset, this water is chilled out of the air and falls to freeze on the surface (or be ingested by plants or animals preparing to hibernate for 2 weeks. Then at dawn, this load of ice atop the surface is supplemented by more precipitation and a general thaw, but again plants and animals ought to scramble to sequester it leaving the surface air rather desertified.

So--biome wise, on land, the air is arid and hot during the day. Clouds might form up high but not rain a lot down to actually water the surface; the lakes and seas will be shrinking all day. If the night side is deep chilled, well below freezing, the terminator storms will involve harsh clashing low dry cold fronts under lofted rainy warm fronts that might drop a lot of precipitation. After the sunset storms though, the chill predominates and weather calms down a lot--no sunlight to drive circulation beyond what is driven by dayside high altitude air pouring down. The middle days of the night cycle will be very calm; what clouds remain will be thin ice cirrus hazing the sky a bit.

Note a huge difference between Nearside and Farside of the Moon at night! On Farside, when it is night, the Moon lies beyond Earth relative to the Sun, Earth sees a full moon (Nearside all lit up) and Farside faces deep space. There is no illumination beyond the occasional lightning flash or fire (most likely near sunrise or sunset, by far) but the planets and stars. Venus would be sometimes visible low on the horizon as morning or evening star and the brightest object in the sky; Jupiter and Mars, and the brighter stars, will be the leading lights. Total illumination levels will be quite low, it is effectively pitch black. On Nearside on the contrary, when it is midnight and the chilled calm of the central disk as seen from Earth prevails, the Moon is new, and Nearside sees a full Earth beyond Luna relative to the Sun. Benford claims the Moon's albedo would be 5 times its current reflectivity, making full moon nights on Earth much brighter...but full Earth then will be some 80 times brighter than an OTL full moon. The cold Nearside night will be lit up pretty well; dim versus proper daylight but probably quite bright enough to see colors or read newsprint.

Broadly speaking this holds in any possible combination of day and night weather; clouds at night I think would be fairly thin even if humidity is a lot higher, since high altitude air pouring in from the day side is pretty well wrung out before it flows nightward. How cloudy the day side is is another story!

I suppose Benford's "Florida" rather than my offered dry air "New Mexico" Luna might be possible after all. If it is pretty hot and also wet on day side, then while air will take up a lot of humidity from evaporation over sea and land, it will also rain a lot. The surface might be maintained in a wet state, with excess water seeping into streams and feeding the lakes and seas to maintain their level despite heavy evaporation. Moisture would be well distributed--just as in "New Mexico" conditions, aridity prevails even near the water bodies.

Can the night side be kept so warm that even in the chilliest days before dawn, the temperature has in fact not dropped below 273 K, freezing, and water remains generally liquid? I suspect that would be too warm to allow for the circulation to maintain those temperatures unless the day side is quite sweltering, too hot for humans to live at all well in.

However, there is also the matter of latitude. At the equator, the day night cycle is as described, but what about the poles?

If we assume night temperatures do fall below freezing, at each pole, air is always flowing over the pole from the cold side, and being below freezing all precipitation from as yet untapped clouds that surge so far north or south will take the form of snow, hail, or ice storms. And the thaw never comes; the cold wind boxes the compass and it is always twilight, but the proper hot day never comes due to the low tilting of the Lunar axis relative to the norm of the ecliptic. Thus ice accumulates, and must form a permanent glacial ice cap. At whatever average rate precipitation does reach the poles, or the lower latitudes where the cold flow prevails to keep temperatures below freezing, that mass of water must in equilibrium be surging equatorward. Low Lunar gravity means that ice sheets too can be six times thicker than Earth's for similar flow pressures so quite a lot of water might be in the polar caps!

But at some latitude, the warm air of the day side must surge there often enough to warm the temperatures in mid day above freezing, and there the glacier will start to melt and feed daytime rivers flowing equatorward (if topography routes them poleward, they will just freeze again so these transition zone rivers pretty much have to flow to the tropics). As we go to lower latitudes, the period in which thaw happens and gives way to increasingly high temperature peaks in the "afternoon" days lengthens as the peak temperatures rise. So even if the tropics are in fact hotlands too hot and humid for humans to prosper in, there will be belts at moderate latitude where peak temperatures are bearable and the average temperature is much lower--because the entire night time is deep frozen and much of the dawn and late afternoon are also below freezing, and probably quite stormy too. But perhaps a week or more of decently warm, survivably calm weather might intervene, and glacial fed streams and rivers making their way to the basins will keep regional moisture at decent levels.

Eventually one comes to a latitude where perhaps peak temperature and humidity is downright deadly, and below those latitudes humans must either stay out or make elaborate shelters against the excessive to us heat. However I would expect local Lunar organisms to be well adapted and able to thrive and move about even if peak temperatures near the equator rise to 50 C or more. This would be a high humidity scenario to be sure.

Heat transport to the dark side probably cannot be so great as to maintain the dark side above freezing, but it might not drop a very far amount below freezing. After all if the ground is covered in snow, the emissivity of the surface is low; the oceans being small and perhaps covered with ice too. Between the Stefan-Boltzmann law meaning low surface temperatures correspond to very low black body emission rates, and the low emissivity of the surface, perhaps quite modest thermal fluxes from the day side can serve to maintain temperatures not drastically below 0 C.

The lower limit would be the temperatures at which oxygen starts to precipitate out; if that starts happening latent heat release should go a long way toward checking further temperature lowering, whereas it would also represent a drop in ambient pressure that would hustle in more dayside sourced upper atmosphere air and thus more heating. Intuitively with air 6 times thicker than Earth's and a planetary circumference 1/4 that of Earth, I doubt it could get that cold, and even wonder if it could get as cold as Terran polar regions ever do. Still there is a lot of room between that and freezing! A snowball dark side is what I would expect, unless the overall humidity is so low the snow is very patchy.

So these are my biome predictions then:

1) substantial and very thick permanent ice caps around the poles, with a surrounding tundra band of chill land that does thaw (on the surface, probably a lot of permafrost under the ground), giving over to fairly well watered taiga (even on a pretty dry moon--as noted, the water simply builds up in the polar zone, until it is thick enough to flow glacially and then as streams.

2) a) New Mexico Luna scenario: depending on how moist it is, either the zone beyond the glacial boundaries quickly dries off, living organisms have desperately sequestered the temporarily flowing water of dawn, and the air dries out, clouds recede very high in the sky and the surface bakes in Saharan or Empty Quarter aridity and heat. But unlike the Sahara or Empty Quarter, a fair amount of moisture was available and living organisms have sequestered it; those plants and animals are quite abundant despite the killing drought, for they are all adapted to fanatically hang on to that water and make the most of it. So, life grimly hangs on and tries to put the abundant solar energy to good use without shedding any water. Of course predation will accidentally release some moisture.

2) b)--if it can be shown that sufficient humidity will not drive tropical temperatures to killing extremes, or anyway that while that happens at low latitudes, bands of survivable peak temperatures will exist between the glaciers and this hot band, then we could have it a lot wetter and presumably greenhouse superheating will not happen. Then indeed the lower latitudes will resemble Florida, or even the Amazon rainforest, in the day.

But unless someone shows me the math I believe the entire night side must be below freezing, which means the poles are above freezing, and in a high humidity version the glacial caps are spreading rapidly, but trimmed aggressively at their edges by aggressively warm daytime temperatures. Even the ultra hot lands in a moderately high greenhouse hotbox for the middle of the day will be plunged into Arctic cold at night. Which of course means the flora and fauna will be quite different from those inhabiting tropical lands on Earth--they will in fact be much more like temperate zone critters.
Obviously my major interest is not in making the Moon a sculpted, convenient park for human use, which is what we would do if we terraformed it to our liking. The "biomes" of the Moon in that case would be whatever we made them to be. We could say "we are making nature preserves for Terran life we have displaced on Earth," but unless we have some kind of supertech to raise Lunar surface gravity by some Star Trek method, the creatures we situate in these delimited grand zoos would not resemble Terran ecosystems really. Imagine the disruption to Terran ecological life cycles, if we simply moved a tract of the Serengeti or the Amazon rainforest or the American southwest--or still more in need of restoration, a tract simulating say a sector of Europe or North America east of the Mississippi, or part of China or India--and seeded them with the same mix of organisms, gifted each tract with an annual seasonal climate cycle and day-night cycle simulating their homes--and stood back and watched. The low gravity would change everything--we would find out whether typical Terran organisms can reproduce and mature normally (or rather, adapted to the low gravity) or not; presumably if there is deterioration of the viability of most organisms, but we could put them in some kind of temporal fast-forward, say we have a time machine and do this project 10,000 years ago, or ten million, over time the less disadvantaged organisms would differentially survive and reproduce and over millions of years of Darwinian evolution honing them, would adapt. Entire niches currently occupied by one set of lineages might be preempted by other organisms whose ancestors are currently adapted to very different ones, and eventually we get comparable diversity and honed adaption, but the overall picture as a spectrum of different ancestors adapting different structures to new purposes is entirely different. Birds for instance would find their flight abilities massive overkill, and the ruthless honing of their body weights to enable flight would be relaxed and they would tend to become a lot more robust (and thus totally unable to survive on Earth were their descendants repatriated there). But meanwhile lots of mammals and reptiles and amphibians who are currently pretty well Earthbound would leap up, probably develop flaps not unlike "flying" squirrels, and get honed to fly around too, and they might in their numbers and already developed more robust body plans crowd most birds right out. Insects already enjoy low ratios of body mass to surface area and would not be so dramatically shifted. The constraints on their size have more to do with limited ability to oxygenate their blood. But bigger animals would lose some constraints on body mass and we'd see some really gigantic creatures (some of whom could also fly, others even bigger would not). Sea and aquatic creatures probably won't change much at all, though we could see some more use of flight by fish and perhaps some marine mammals to jump from one water body to another (more important on a world with its water bodies all separated from each other).

In the ASB version I like better, I imagine the ASBs do pretty much this, but not with any agenda to produce zoo type preserves. They just reform the surface, down to say 100 meters or so, so the soil chemistry is more like Terran, provide the new atmosphere and as much hydrosphere as is consistent with maintaining reasonably warm but also cool temperature ranges on the daylit side, and seed tracts of new land pretty eclectically with copied samples of all kinds of Terran ecosystems, as is. And using time travel or alternate dimensions with faster time evolution, fast forward, I suppose 10 million years or perhaps more is suitable, and just see where, subject to changed gravity, more extensive upward range (and I suspect even the highest Lunar elevations will differ little from the average "sea" level, so most of that range is for long range flight or even organisms rafted into the upper troposphere) and the rather severe day/night cycle over a full Lunar month I expect, it all comes down. Mobility will be easy; plant spores and seeds will tend to be lofted long distances, flying creatures will be abundant and carry more seeds as well as dispersing their own lineages, so pretty much the entire ecodiversity of Earth is the seedbed of whatever mix of creatures wind up dominating the biomass, graded chiefly by latitude and that generally mildly versus Earth. Lunar surface area in total is comparable to the continent of Africa, so that gives some idea of the range, except that some climate zones found there on Earth might be nonexistent--a pretty dry Luna would be all Sahara-Kalahari-Sahel-Namibia and most surviving creatures would come from there, whereas a warm moist Luna might be overwhelmingly descended from Congo rainforest critters. (Except as noted, the seeding is from all over Earth; kangaroos compete with ostriches and rheas and horses, jaguars with arctic foxes, eucalyptus with redwoods, etc). And unless I can show that actually the night side temperatures do not drop below freezing, which I doubt very much if the day side is cool enough for Terran astronauts not to perish roaming around in light clothing at the warmest times, the polar caps of course replicate Greenland or Antarctica for the most part, except the ice is even thicker and holds a significant share of all the water; something like tundra must also exist on the margins of the great polar glaciers.

The world the hypothetical astronauts find--whether we do a mid-1960s ISOT late enough for the USA to be locked into an Apollo commitment but early enough to allow the redesign of the Lunar landing approach, or do it in a few years hence when SpaceX "Starship" or Blue Origin New Glenn is up to the task of an expedition--would thus be well adapted to the low gravity and bizarre range of climates, most of which would resemble vaguely Terran temperate ones but with the "annual" and day cycle fused into one with alternating much shorter winter and summer.
Something else I wanted to mention in context of ATL Apollo--OTL the Apollo 8 mission was essentially an opportunistic political stunt. Saturn V as a launcher was ready and largely tested, the CSM was ready, the LM was still undergoing development, meanwhile there was concern the Soviets might do a Lunar flyby and claim to have beaten the Yankees "to the Moon." They could not reasonably do this with the stipulation of making Lunar orbit and then boosting again to trans-Earth trajectory for a return, but the much lower delta-V required to just fly by might have been possible (this is what the Zond test program, with quite limited success to be sure, appeared to be forecasting). So Apollo 8, at some risk, was tasked to do better and use the considerable delta-V of the Service Module to brake into LLO and then later burn back to Earth--had the CM main engine failed between these burns the crew would have been doomed, but of course the same would be true of such a failure on any future Moon landing mission, so it was an important demonstration of capability technically. (Though just proving the engine could be and had been done in LEO). Also had an Apollo 13 type failure occurred they would have had no LM lifeboat, and by the way the ATL direct descent ascent program I sketched out for myself would run a similar no backup risk--no LM provided you see.

But in the ATL, it would actually be operationally important to take a good survey look at the Lunar night side--not that any first wave mission would propose to risk exploring in that presumptive deep chill! Though it has advantages; in the middle of the night away from the terminator storm zone, the air should be pretty calm for instance, while the day side would be more turbulent. If in fact Lunar day equilibrium is too hot and humid for humans to endure the mission might in fact have to be repurposed to a night landing only. (I hope to avoid that necessity of course). Still, it is both for mission planning and scientifically useful to know a lot about detailed conditions in the Lunar night. As noted, trying to observe Farside in the night is pretty difficult, what with illumination coming only from starlight, whereas if Nearside is in night, it is brightly lit by Earthlight, the Earth appearing full in the Lunar sky. So a purely orbital expedition, or several, are well in order for other reasons than a dubious test/demonstration or political stunt to beat the Russkies. Orbiting as close as possible (given the extensive atmosphere producing air drag), they would be able to observe Farside in day conditions (again, actually going there is penciled in for tentative future missions, not immediate, but all the more reason to survey it from orbit, for its own distinct features and for a sample of what Nearside day conditions are) while also seeing what happens to their Nearside immediate target landing zones over night. This could be important--if a prospective landing zone turns out to be in the watershed of a big snowfall concentrated by local conditions every night, and therefore flooded heavily in the earlier morning Earth days of the two week long Lunar day, that is probably a spot to avoid for instance! And scientific value is inherently high. Given that I think the strategy will be direct descent and ascent, the opportunity OTL of every Lunar landing mission also involving leaving the CSM pilot in LLO to make observations while the other two fool around on the surface landing site is not present, so separate orbital missions are in order quite aside from step by step preparation for landing. (An Apollo 10 style dry run almost landing is not possible; the equivalent would be to send an uncrewed vessel to land robotically and see if it makes it down or not, then test its ability to launch a dummy CM back to Earth).