I want to return to Mars this morning because an emerging idea on how to terraform it is in the news. The idea is to block infrared radiation from escaping into space by releasing engineered dust particles about half as long as the wavelength of this radiation, which is centered around wavelengths of 22 and 10 μm, into the atmosphere. Block those escape routes and the possibility of warming Mars in a far more efficient way than has previously been suggested emerges. The paper on this work even suggests a SETI implication (!), but more about that in a moment.
Grad student Samaneh Ansari (Northwestern University) is lead author of the paper, working with among others Ramses Ramirez (University of Central Florida), whose investigations into planetary habitability and the nature of the habitable zone have appeared frequently in these pages (see, for example, Revising the Classical ‘Habitable Zone’). The engineered ‘nanorods’ at the heart of the concept could raise the surface temperature enough to allow survivability of microbial life, which would at least be a beginning to the long process of making the Red Planet habitable.
As opposed to using artificial greenhouse gases, a method that would involve vast amounts of fluorine scarce on the Martian surface, the nanorod approach takes advantage of the properties of the planet’s dust, which is lofted to high altitudes as an aerosol. The authors calculate, using the Mars Weather Research and Forecasting global climate model, that releasing 9-μm-long conductive nanorods made of aluminum “not much smaller than commercially available glitter” would provide the needed infrared blocking that natural dust cannot, and once at high altitude settle more slowly to the surface.
What stands out in the authors’ modeling is that their method is over 5,000 times more efficient than other methods of terraforming, and relies on materials already available on Mars. Natural dust particles, you would think, should warm the planet if released in greater quantities, but the result of doing so is actually to cool the surface even more. Let me quote the paper on this counter-intuitive (to me at least) result:
Because of its small size (1.5-μm effective radius), Mars dust is lofted to high altitude (altitude of peak dust mass mixing ratio, 15 to 25 km), is always visible in the Mars sky, and is present up to >60 km altitude (14–15). Natural Mars dust aerosol lowers daytime surface temperature [e.g., (16)], but this is due to compositional and geometric specifics that can be modified in the case of engineered dust. For example, a nanorod about half as long as the wavelength of upwelling thermal infrared radiation should interact strongly with that radiation (17).
Edwin Kite (University of Chicago) is a co-author on the work:
“You’d still need millions of tons to warm the planet, but that’s five thousand times less than you would need with previous proposals to globally warm Mars. This significantly increases the feasibility of the project… This suggests that the barrier to warming Mars to allow liquid water is not as high as previously thought.”
Image: This is Figure 3 from the paper. Caption: The proposed nanoparticle warming method. Figure credit: Aaron M. Geller, Northwestern, Center for Interdisciplinary Exploration and Research in Astrophysics + IT-RCDS.
Strikingly, the effects begin to emerge quite quickly. Within months of the beginning of the process, atmospheric pressure rises by 20 percent as CO2 ice sublimes, creating a positive warming feedback. Note this from the paper:
On a warmed Mars, atmospheric pressure will further increase by a factor of 2 to 20 as adsorbed CO2 desorbs (35), and polar CO2 ice (36) is volatilized on a timescale that could be as long as centuries. This will further increase the area that is suitable for liquid water (6).
That said, we’re still not in range for creating a surface habitable by humans. We have to deal with barriers to oxygenic photosynthesis, including the makeup of the Martian sands, which are laden with potentially toxic levels of nitrates, and an atmosphere with little oxygen. Toxic perchlorates in the soil would require ‘bioremediation’ involving perchlorate-reducing bacteria, which yield molecular oxygen as a byproduct. We’re a long way from creating an atmosphere humans can breathe, but we’re in range of the intermediate goal of warming the surface, possibly enough to sustain food crops.
Addendum: I made a mistake above, soon caught by Alex Tolley. Let me insert his comment here to straighten out my mistake:
“… which are laden with potentially toxic levels of nitrates,”
I think you misinterpreted the sentence from the paper:
“…is not sufficient to make the planet’s surface habitable for oxygenic photosynthetic life: barriers remain (7). For example, Mars’ sands have ~300 ppmw nitrates (37), and Mars’ air contains very little O2, as did Earth’s air prior to the arrival of cyanobacteria. Remediating perchlorate-rich soil…”
300 ppm nitrates is very low and will not support much plant or bacterial life. [You want ~ 10,000 ppm ] That is why N and P are added to simulated Mars regolith when testing plant growth for farming or terraforming. IIRC, there have been suggestions of importing nitrogen from Titan to meet its needs on Mars.
Thanks for catching this, Alex!
Although nanoparticles could warm Mars… both the benefits and potential costs of this course of action are now uncertain. For example, in the unlikely event that Mars’ soil contains irremediable compounds toxic to all Earth-derived life (this can be tested with Mars Sample Return), then the benefit of warming Mars is nil. On the other hand, if a photosynthetic biosphere can be established on the surface of Mars, perhaps with the aid of synthetic biology, then that might increase the Solar System’s capacity for human flourishing. On the cost side, if Mars has extant life, then study of that life could have great benefits that warrant robust protections for its habitat. More immediately, further research into nanoparticle design and manufacture coupled with modeling of their interaction with the climate could reduce the expense of this method.
That’s a robust way forward, one the authors suggest could involve wind tunnel experiments at Mars pressure to analyze how both dust and nanomaterials are released from modeled Mars surfaces, from dusty flat terrain to the ice of the poles. Large eddy simulations (LES) are ways to model larger flows such as winds and weather patterns. Deploying these should be useful in learning how the proposed nanorods will disperse in the atmosphere, while local warming methods also demand consideration.
A question I had never thought to ask about terraforming was how long the effects can be expected to last, and indeed the authors point out how little is known about long-term sustainability. A 2018 paper on current loss rates in the Martian atmosphere suggests that it would take at least 300 million years to fully deplete the atmosphere. The big unknown here is the Martian ice, and what may lie beneath it:
…if the ground ice observed at meters to tens of meters depth is underlain by empty pore space, then excessive warming over centuries could allow water to drain away, requiring careful management of long-term warming. Subsurface exploration by electromagnetic methods could address this uncertainty regarding how much water remains on Mars deep underground.
Image: Will we ever get to this? The ‘nanorod’ approach oculd be the beginning. Credit: Daein Ballard, Wikimedia Commons CC BY-SA 3.0.
The SETI implication? Nanoparticle warming is efficient, so much so that we might expect other civilizations to use the technique. A potential technosignature emerges in the polarization of light, because a terrestrial world with a magnetic field will show the interaction of polarized light with the planet’s atmosphere, the latter conceivably laden with the nanoparticles at work in terraforming. Polarization will occur when light interacts with nanoparticles, aerosols, or dust in the atmosphere or the magnetic field. This would be an elusive signature to spot, but not outside the range of possibility.
In the absence of an active geodynamo to drive a magnetic field, Mars would not be a candidate for this kind of remote observation. But an exoplanet of terrestrial class with a magnetic field should, by these calculations, be a candidate for this kind of study.
The paper is Ansari et al., “Feasibility of keeping Mars warm with nanoparticles,” Science Advances Vol. 10, No. 32 (7 August 2024). Abstract / Preprint. Thanks to Centauri Dreams reader Ivan Vuletich for the pointer to this paper.
Perhaps adding a small amount of iron to the construction would help, it would be magnetisable allowing it to be propelled into the air and removed as and when.
Aluminum or Aluminum Oxide is toxic. In humans, it damages the lungs. IDK what it does to air-breathing animals, but probably something similar. If used to terraform Mars, it will have to be removed from the air, and probably the water supply before the fauna can occupy the surface.
To my way of thinking, this solution to warm the planet to ultimately terraform it, makes it toxic to animals and humans. Can it be transient, removing it from the air once the warming is underway, and from any water once the atmosphere supports clouds and rain?
I prefer the solution that KSR used in his Martian trilogy novels – put mirrors (solettas) in orbit to increase the sunlight reaching the surface. Yes, the masses are pretty vast, but they can be controlled and are not toxic. Robotic mining of a NiFe asteroid to build the mirrors, coupled with water as a propellant to move the mirrors into position, seems like a good way to leverage advanced robotics. Power for the solar thermal; engines could be provided by concave mirrors, solar PV panels, or beamed from the Martian surface.
As for the perchlorates, there are several ways to mitigate it.
The bigger question is whether we need to terraform Mars at all. Living on the surface might be better done under ever-expanding habitat below ground or under enclosures. This keeps contamination in both directions under tighter control. We may prefer to live in space cities, with periodic travel to planetary surfaces for work and recreation.
Toxicity shouldn’t be a problem by the time the surface is ready for colonization. Any hydrological cycle put in motion will quickly rain out both the engineered dust as well as natural Mars dust, leaving clear, blue skies, and clouds–like on Earth.
Maybe. But as you know, metal and organic material contamination remains in waters that collect in rivers, lakes, seas, and aquifers. California has selenium, lead, copper, and arsenic contamination in water supplies. These materials enter the food chain and are difficult to remove. Mercury still contaminates tuna reducing the amount that is recommended to consume to prevent neurologic damage. Leakage of nuclear waste from the UK’s Sellafield reactors from drums dumped in the Irish Sea make it the most radioactive contaminated waters on the planet.
All this experience should be a cautionary warning not to try the “cheapest” quick fixes to achieve some goal with unforeseen consequences.
Or would it just be relatively much easier to bioengineer humans to adapt to current Mars and many other worlds, plus space itself…
https://www.centauri-dreams.org/2022/11/04/in-person-or-proxy-to-mars-and-beyond/
It would certainly ensure our survival as a species.
I don’t know what sort of gene engineering will allow humans to live on the surface of Mars in its present state. With no O2, we would have to use anaerobic respiration which is very poor for energy production. Radiation is not going to be easy to mitigate either. I can see humans living underground in pressurized habitats making occasional forays onto the surface. This is the scenario of Alexander Jablokov’s “Red of Dust”. I think technology is the better way to go rather than changing humans that much. Even KSR’s Mars trilogy only modified humans to be able to breathe a thinner atmosphere. Neither author dealt with the issue of reduced gravity. Until we do some good partial gravity experiments, we won’t know how much g we need to stay healthy.
If we are to walk on the surface of Mars, or any other planet or moon, it would be safer to do this using a physical avatar. It needn’t be fully humanoid, just enough to move about, see hear, smell (?), and grasp objects. The person would be safely ensconced in a shirt-sleeve environment within a short distance to reduce communication latency, wearing the needed control gear to feel present on the surface (or any other suitable location and travel mode). This solves most of the problems of living off Earth. Even g forces could be managed. KSR’s “Red Moon” has centrifuges in the Chinese lunar cities to create Earth-normal g.
There are other hybrid solutions to living on hostile surfaces, from John Varley’s use of protective skin covering force fields to protect against low pressure, with one lung replaced to support canned O2 for inspiration. Robert Sawyer has replacement robotic bodies with downloaded minds living on Mars and elsewhere.
While gene engineering is only just starting to offer body enhancements, right now we seem to use it as a “magic pixie dust” to solve a host of technology issues for human body enhancement, a role nanobots had in 1990s fiction. The movie “The Titan” was an extreme example of gene engineering humans to live on Titan.
A lower tech way to at least partially terraform Mars, is that taken in Ian McDonald’s “Digging”. Where there is a multi-generation project to dig a hole in Mars thats deep enough to sustain a human tolerable pressure.
Audio version here: https://www.youtube.com/watch?v=ukvPozyi4sE
As to nano particle toxicity and whether Solletas are better, any serious terraforming project is going to have to take a systems approach.
The durability of nano particles and the costs of any cleanup, if needed, will need to be weighed against the 5000x leverage potentially afforded by the method. I personally suspect that the nano particles will behave like volcanic dust on Earth and will fall out of the atmosphere on year – decade time frames, though it could well be worth engineering less durable particles, a bit like the current push for bio-degradable plastics here on Earth.
I have to admit, though that at first glance these nano particles sound a bit like a Martian version of asbestos.
As to whether Soletas or nano particles are better, the correct question to ask, is what are they good at? I could easily imagine Soletas being used to strategically warm areas of the poles, may be with a few strategically placed civil nuclear bombs for funsies :-). While the nano particles role is to thicken up the atmosphere to help kick start a runaway green house effect. But the trick is the get the green house effect to runaway at a rate thats manageable.
I actually agree that it will likely be machine avatars that spread out into the Sol system and galaxy. However, if there is a way to biotech beings to live in all kinds of environments, I am for that as well.
Think of it as nature adapting to evolve once again, only this time she is using our brains to advance the process rather than playing trial and error for the next 7 million years.
I try not to use biotechnology and genetic engineering as “magic pixie dust”, even if I am not an expert on the subject, because I know it will improve and one day we will be able to do the things I see it doing. Whether we actually use it is another matter, but I still see its possibilities.
Just like if you told someone in 1950 that the monster rom-sized computer they are using with barely enough brain power to operate an insect would one day be thousands of times more powerful and be held in one’s hand or pocket simultaneously.
I was unaware of the film The Titan. While I have yet to see it, from what I read of the plot it seems to be yet another science fiction film that has to turn something non-human into the bad guy for drama. Just like with aliens and AI.
My problem with that is it may stir up debate on the pros and cons of these topics, but how truly accurate and informative is it?
@Ljk
The computer argument is based on hindsight. When computers used valves, there was no obvious expectation that they would become smaller, especially with the invention of transistors. Even when transistors became available and appeared in electronic devices (e.g. transistor radios) there was no expectation they would be printable in monolithic chips. I remember the SciAm article about integrating 4 transistors!
You may remember Drexler pushing nanotechnology which spawned a scifi literature about swarms of nanobots. Machine-like nanotechnology never happened as it was built on a false premise, Today nanotechnology just means nanometer particles.
Gene engineering is based on manipulating existing biology. Therefore it will be achievable once we can truly design complex biological systems. However, scifi/horror literature twists the changes to work to slowly change a complex organism’s phenotype. This cannot happen. (The technology of The Titan, as well as numerous alien infection transformations is BS. Changes will be much more subtle, including neural and cognitive ones.)
We should not assume extreme extrapolations. Physics, chemistry, and biology just get in the way. All technologies follow logistic curves, a lesson that needs to be relearned. We do not know where we are on that curve with gene engineering. I believe we are just on the lower slope at present, but I could be wrong.
Managing genes is not quite like lego blocks, on account of gene interactions further complicated by epigenetic interactive controls and even protein-gene interactions.
More complicated than any board games: the consequences are fine-tuned over evolutionary time.
@Robin
Let’s not go too far in the opposite direction by implying gene engineering is too complicated. We know that we can successfully alter plants with genes, adding or removing them. We can do similar things with animals, of which the 2 most interesting to me are the “gene drive” used to control mosquitoes and the method to build simple computation and sensors in bacteria.
Two decades ago the modeling of gene networks was being achieved, and I have little doubt that more powerful machine learning will increase that capability so that intercellular interactions can be solved to reverse engineer embryo development with high fidelity.
Yes, as you say, there are complicating factors, but in principle, they can be modeled with enough fidelity that we will have hopes of creating significant changes that work well. De-extinction work will add to our expertise.
But we should always remember the immortal words of Ian Malcolm: “…but your scientists were so preoccupied with whether or not they could that they didn’t stop to think if they should.”
I will agree with Alex Tolley on whether we need to terraform Mars. I loved the idea as a young adult, but due to Mars lower gravity, it can’t hold on to a thick atmosphere in deep time. We would have to add a lot of atmosphere to the planet which would be very expensive. Mars dust already has a lot of iron and aluminum. Dust will make the planet cooler which is one idea scientists have already thought about fighting climate change on Earth.
Warming the planet would definitely add to the atmosphere, but it would also increased the jeans escape. Large mirrors in orbit and surface albedo changes are a few ideas scientists have theorized. We would have to melt the polar ice caps to get enough of an increase of atmosphere. Much of Mars atmosphere has been lost and carbon dioxide freezes at a much colder temperature than water. Most of the polar ice caps are made of water and there is not a lot of frozen carbon dioxide on Mars, but a lot of permafrost. If we melted that and the ice caps the permafrost would increase the atmospheric pressure, but we would really have to add some atmosphere to get to what Mars originally had in it’s early history. Much atmosphere has been lost since Mars formation.
300 million years of seep time of Earth puts us back into the Carboniferous. I don’t think that sort of atmospheric longevity, would be a design requirement for a Mars terraforming project, assuming that it is viable.
I would settle for 3 million years or even 300 – 30 thousand years.
Channeling Edgar Rice Burroughs from the last article, the lowest figure could inspire some interesting SF… Centuries from now, after a disaster on the Mars terraforming project. Environmental conditions on Mars go into reverse with the atmosphere slowly thinning and surface water slowly freezing out. Faced with a dying planet, a desperate Martian civilization constructs a canal network to bring water to the thirsty Equatorial regions…
Carl Sagan also came up with the ironic idea of using canals as well to terraform Mars in the Cosmos episode “Blues for a Red Planet”.
You may watch the full episode here:
https://archive.org/details/cosmos5bluesforaredplanet360p#:~:text=Carl%20Sagan%20cosmos%20series.
Or here:
https://www.organism.earth/library/document/cosmos-5#:~:text=Cosmos,%20Episode%205.%20October%2026,%201980.%20Carl%20Sagan.
Percival Lowell will be vindicated yet!
https://www.astronomy.com/science/the-story-of-percival-lowell-this-week-in-astronomy-with-dave-eicher/
Hi Geoffrey
Every Comments “Expert” drags this one out every time Mars terraforming hits the news. Do you really want to coin a truism? It used to be a major unknown, but MAVEN’s observations have given it actual parameters – 2 kg/s for the whole Martian exosphere. Sounds like a lot – about 64,000 tons per annum. Over a billion years it’s equivalent to 0.63 metres of water spread over the Martian surface. Not negligible, but not major either.
Jeans Escape is only an issue for very light molecules and atoms at the very top of the exosphere on a planet Mars’ size – typically it’s hydrogen that’s the issue. Keeping it out of the stratosphere via a cold trap there might be sufficient to make it a non-issue on very long timescales.
The MAVEN extrapolated losses from Mars over the last four Eons are clearly driven mostly by the very high Solar Wind speeds in the very early days of the Sun – the first Eon causing the most loss. Since then the losses from Mars are negligible even over Eons of time, with Jeans losses being the least of the various processes involved.
There are many problems on Mars for humans: radioactive, sharp, fine, poisoned-by-perchlorat regolith, no atmosphere, no magnetic field, no nitrates on Mars (for plants), not enough sun, far awar (so long travel at 0g), not enough gravity for longterm human habitation, tough conditions for outside work etc.
Geoengineering might solve some of these, but big obstacles would still remain. Also, geoengineering takes aeons to complete, in the meantime we need to survice on this planet (and currently do not great here).
I doubt human colonisation of other celestral bodies. But I’m all in for robotic exploration.
Cities of Mars…
https://m.youtube.com/watch?v=6DyNeWloBss&si=tOUGBF3PIb7lN_2e&fbclid=IwZXh0bgNhZW0CMTEAAR0RGjQ3k2THBbxqYLYEHUzFgymUGee0vv5K1AbAka8eXqh1nhyz_hEybKk_aem_l3ClD_M9Ydq_dDjiAIJIYA
Perhaps better to collect light at the sun lagrange point and convert it into a laser light that is set to be absorpted by the carbon dioxide ice at the poles. This will cause the ice to sublime thickening the atmosphere.
https://astrobiology.com/2024/09/projections-of-earths-technosphere-i-scenario-modeling-worldbuilding-and-overview-of-remotely-detectable-technosignatures.html
Projections of Earth’s Technosphere. I. Scenario modeling, Worldbuilding, and Overview of Remotely Detectable Technosignatures
By Keith Cowing
Status Report
astro-ph.EP
September 4, 2024
This study uses methods from futures studies to develop a set of ten self-consistent scenarios for Earth’s 1,000-year future, which can serve as examples for defining technosignature search strategies.
We apply a novel worldbuilding pipeline that evaluates the dimensions of human needs in each scenario as a basis for defining the observable properties of the technosphere. Our scenarios include three with zero-growth stability, two that have collapsed into a stable state, one that oscillates between growth and collapse, and four that continue to grow. Only one scenario includes rapid growth that could lead to interstellar expansion.
We examine absorption spectral features for a few scenarios to illustrate that nitrogen dioxide can serve as a technosignature to distinguish between present-day Earth, pre-agricultural Earth, and an industrial 1,000-year future Earth. Three of our scenarios are spectrally indistinguishable from pre-agricultural Earth, even though these scenarios include expansive technospheres.
Up to nine of these scenarios could represent steady-state examples that could persist for much longer timescales, and it remains possible that short-duration technospheres could be the most abundant. Our scenario set provides the basis for further systematic thinking about technosignature detection as well as for imagining a broad range of possibilities for Earth’s future.
https://astrobiology.com/wp-content/uploads/2024/09/Projections-of-Earths-technosphere1.png
A diagram of the worldbuilding pipeline developed for this study. The pipeline begins with the global and technology factors that define each scenario from Table 5 and other assumptions common to all scenarios (grey). These inputs are given to the Claude LLM, which then generates a description of the world (blue). Additional narrative and descriptions of the planetary bodies are added manually (purple). This information provides the basis for a human needs assessment that determines the different uses of land on each planetary body (orange). These results are used to describe the physical technosphere and potentially detectable technosignatures (yellow), which provide recommendations for technosignature detection (green). — astro-ph.IM
https://astrobiology.com/wp-content/uploads/2024/09/Projections-of-Earths-technosphere2.png
A diagram of the spatial distribution of the technosphere (orange) and biosphere (green) for each of the ten scenarios. Centers or “poles” of the technosphere are marked with X. Note that three cases involve a technosphere that remains limited to Earth and/or the moon (S4, S7, S8), and two cases involve a complete separation of the technosphere from the biosphere (S9, S10). — astro-ph.IM
Jacob Haqq-Misra, George Profitiliotis, Ravi Kopparapu
Comments: Submitted to Technological Forecasting and Social Change
Subjects: Physics and Society (physics.soc-ph); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Popular Physics (physics.pop-ph)
Cite as: arXiv:2409.00067 [physics.soc-ph] (or arXiv:2409.00067v1 [physics.soc-ph] for this version)
https://doi.org/10.48550/arXiv.2409.00067
Focus to learn more
Submission history
From: Jacob Haqq-Misra
[v1] Fri, 23 Aug 2024 12:55:19 UTC (570 KB)
https://arxiv.org/abs/2409.00067
The major greenhouse gas on Earth is water vapor.
Mars only has 210 ppm of water vapor.
If Earth had only 210 ppm of water vapor, it would be a lot colder.
But the problem with Mars or our Moon is not that it’s cold.
One might the problem with Mars, is it gets less solar energy than the Moon, though Mars gets more solar energy from solar panels- in terms of electrical power. Earth only gets electrical power from solar panels for about 6 hours of 24 hour day, and Mars gets 12 hours of solar power per it’s 24 hour day. That’s called peak solar hours, Mars doesn’t have peak solar hours, it can full amount of sunlight as long as the sun in the sky.
With Moon or Mars, you wouldn’t have fixed solar panels as we have on Earth [it would be dumb] instead the solar panels would track the sun from dawn to dusk.
And with Moon and Mars, the elevation matters quite a bit, and with high elevation, one can get significantly more than 12 hours per day. With lunar poles there are places which provide sunlight 85% of the time. Though at low elevation at poles one can little little sunlight. One has similar thing with Mars and polar regions are better {which never vaguely the case with polar regions on Earth}. And in polar region of Mars and Moon, there is not much distance between time zone. Or with spot on Moon polar region, due to elevation- you getting different time zones. But you run powerlines, in short distance one get to different time zone.
But with the surface of Mars [which doesn’t keep on pointing at sun] on average gets less solar energy, than earth surface. But lunar surface during the day only get hot during “peak solar hours”- the few hours nearest noon. Or at dawn on the Moon the ground is quite cold, and before sun set, it is likewise cold. But solar panel at dawn or near sunset on Moon, because they point at sun, will get full solar energy {an average of 1360 watts per square meter}.
So, in terms of harvesting solar power, the Moon is better than Mars, and Mars is better than Earth.
And what you want to do on Mars {and the Moon} is mine a lot of water. On Mars you make lakes without dome over it and increase local water vapor on Mars {it makes it a bit warmer, locally] but what’s more important one get snow on the ground within tens miles of your lake, and it improves real estate value around the lake.
One could call the town, Christmas, and you easily see it, from orbit.
Perhaps both approaches, nano particles under the aerogel. Cleaning the aerogel is a big issue though.
https://m.youtube.com/watch?v=10WG6bFvsgE
Maybe another way is to have huge amounts of solar cells on the surface which is used to create huge currents through any brines under ground which heats the surface from underneath. Either way it will be a huge under taking perhaps better to have an orbital space station with space elevator.
It’s interesting how strong aerogels are in compressive mode, 1000’s times their weight ! graphene ones can be near a billion times. Thats enough for extremely high towers and would allow for very large aerogel domes to be build where we could put habitates under AND heat the surface of the planet. Also the heat will rise from the ground and collect at the top giving an increase in heat collection for a raised habitate.
https://pubs.rsc.org/en/content/articlelanding/2018/nr/c8nr04824j
Tangential:
It seems that a water reservoir in the equatorial Martian crust is estimated to be 10.5-20 km below the surface, based on marsquake measurements by the Insight lander. If so, this aligns with estimates of low thermal conductivity.
Now we need to find shallower pockets that may be allowed by volcanic activity or impactors. If found, we might then be able to drill down to reach these pockets and seek life, while prospecting for water for a Mars base.
Drill into that and it will be quite warm and would more than likely reach the surface at high pressure.
https://www.pnas.org/doi/10.1073/pnas.2409983121
It would be a huge resource that’s for sure, game changing.
We have drilled down that far before on earth so not impossible.
It appears to me that the immediate issue for survival on the surface of Mars is access to resources that allow a closed life cycle which includes air, water and food. The water is much more accessible and plentiful than it is on the Moon and the issues of constructing shelter are much the same. In just about any other matter, save the distance, Mars is more habitable than the Moon. If the two bodies traded places, we wouldn’t even think much about lunar exploration.
Back in the early 1960s, Analog s-f magazine editor John Campbell wrote several articles for the magazine about terraforming. He had a whole supply of such ideas. But in any case, reading the articles back then, it left me with lingering notions about taking water ice resources from the outer solar system and dropping them on Mars or the moon. To the extent that I ever explored it, it looked possible to create multiple flyby paths that could end in surface deliveries. Such pipelines could be established with some payload fraction. Tethers could soften the landing on the Moon, but I suspect the last phase for Mars would be impact. Rather than trying to bail out a sea with a bucket, it is more like taking a bucket to the shore and attempting to fill up a dry one.
But seas do not necessarily exist in the equivalent of planetary buckets. There is moisture in the interiors below them, its equilibrium based on pressure and temperature closer and closer to a core significantly hotter than the respective surfaces. That the core of Mars is significantly cooler than Earth’s is likely true. But both Earth and Mars appear to be structured consistent with vast subsurface stores of water. What the phase diagram looks like at the depths, pressures and temperatures for the two planets, conceivable paths to the surface would be eruptions of steam. And with the earth over eons, what with subsurface cooling or leakage of energy, the thermal contours would retreat toward the center. A consequence here would be lower ocean levels. Exceptions might be impact events or complicated events triggering ice ages such as ended 500 million years ago.
For Mars, this geological view would be reduction to no surface oceans at all. Clearly, much water vapor dissociated and escaped into space, but one could look at it as “sea level” falling kilometers below the surface as well.
Hence, one could supplement Mars surface water with icy planetoid bombardment as Campbell’s writing suggests, or drilling down to where the ocean resides. Likely, there are subsurface lakes in between and the boundary is fuzzy at that. Not realizing that there was a large subsurface “sea”, tapping into the earlier known hydrosphere ( e.g., from terrestrial radio mapping decades back), this still makes a significant target. But even better now.
As to all the concerns of toxicity enumerated, one would not want to be a colonist oblivious to these. But the issues might be akin to what to warn researchers headed to Antarctica. You can’t live there like you would on the California coast either. Yet there still could be advantages to residency in either place, personal or mission related. Individual and for humanity overall.
Unless one goes polar there too, the sunrise and sunset is regular overall, but reduced to two thirds….
Water is there in very large quantities but frozen. All you really need is power to break down water in hydrogen and oxygen. Nothing wrong with a pure O2 atmosphere just need lower pressure of a few psi that’s all. The hydrogen can be allowed to escape or transported off world via a tube type space elevator or made into hydrocarbon feed stocks.
The theme of Asimov’s “The Martian Way” is tangential to this. Mars needs Earth’s water for reaction mass for their spacecraft. To stymie an Earth embargo on water, the Martians haul a massive ice chunk from Saturn’s rings. Today, we know they could acquire a much closer source of water – Ceres. But now that we know that there are subsurface glaciers on Mars, and liquid water at depth where it is warmer it will be easier to drill for it rather than import it.
The Martian Way (1952).
Also, see my post on subsurface water that implies a number of worlds in our system could have subsurface HZs. Is Most Life in the Universe Lithophilic?
The appeal of this project is more fundamental than terraforming. The authors are saying they can paint Mars a different color with 10 individual particles per milliliter. You could paint it green the same way, I think. (shorter rods, even) If this works, a performance artist or music promoter could spray these rods over a scenic valley and give it a purple sky – they might have to splurge and do a few hundred per mL since they have less height to work in, but at least they don’t have to do a whole planet. Or if we go the other way, how about dispersing longer rods around Mars, giving them VLBI capability, and turning the planet into a radio telescope? Do the same with the Solar system, even if the density must be lower.
It sounds very appealing, but I have this nagging feeling I’ve never seen someone pour out a bottle of pink air dyed with this technique. It ought to be vastly more efficient than a smoke bomb, after all. But would these rods really act like an ideal gas? I wonder if they would knock into one another and split themselves to pieces, or become tangled into a clump, or generate a Casimir effect / London disperson force type interaction and come down as a sort of … rain. I want to see what this technology does on Earth before I feel optimistic about another planet. I think the only prior work about the rods cited in that paper is a theory paper from 1947.
The “Lithophilic” article above is a keeper. Plenty of illustration and detail.
But then again, once the proposition for Mars is generally acknowledged, it is likely to complicate the access to this feature; for reasons much the same as those surrounding preparation for Viking landings. Discussing these matters, one practically has to have two hats nearby one’s seat at the table: one for human settlement or living support – and the other for the safeguard of whatever remnants of life might reside under the Martian surface. The scientific community cannot resolve whether Martian life exists under the surface without further investigation. And further investigation would require more infrastructure. My hope is that we can have our cake and eat it too.
Moving beyond that stumbling block, then the terrestrial life cycle transported to Mars could still be contaminated by Martian microbial intrusions into hydroponic gardens, not to mention less guarded systems.
But now that we have lived through many viral outbreaks here on Earth based on agents we had never heard of before, it might not be that much more of a risk than if we simply had stayed here at home. Unless I missed it, I don’t think there has been a resolution of why methane traces appear in the Martian atmosphere. No known cattle, no known termites…nor meadows or forests for their foraging.
It seems to me that Mars cannot actually be turned into an Earth-like world. The goal of “terraforming” should be more modest. Get the atmospheric pressure high enough above the Armstrong limit such that people do not have to wear space suits to walk around outside. You only need breathing gear. This may or may not be possible for Mars.
As noted, we are all caught up in a debate with an issue that is difficult to define.
The simplest term I can think of is “habitability”. Particularly with respect to Mars and, by comparison, the Moon. One could argue, of course, anything above the Earth’s atmosphere is questionable, but at this point in history, what with long periods of orbital living, we are at least testing our abilities. It might be argued than living on a surface such as the moon or Mars would be easier.
Consequently, I can cite particular sets of data, but I doubt if these settle the question as to whether human efforts on Mars are doomed or not. More likely, it might be an issue of successive waves or reinforcements. If and when they arrive and how much resource can be directed to small Earth-like bubble environments.
Still, toward this end I would like to refer back to a development that made news in 2005 and then vanished from view or discussion. The Mars Express Orbiter High Resolution Stereo Camera identified an “ice lake” in a 70.5 degree North 103 degree East crater in the northern plains ( Vastitas Borealis) a 10 kilometer wide feature in the center of a 35 km wide crater. Neither feature, so far as I know, ever received a name. The lake is ( was?) about 2 kilometers below the crater rim and the color of a robin’s egg in the imagery. The terrain was brownish-pink and the inside Eastern crater wall was capped by frost, likely CO2.
Not flowing water, but that’s a lot of surface ice. Canada could have simultaneous high school national playoffs with such an expanse. I suspect that the ice is solid to the bottom of the crater. But it is also the proverbial tip of a larger iceberg in the sense that if it exists exposed, there are similar features all over Mars: at deeper depths in lower latitudes – and less exposed elsewhere near to the poles.
Since then the seismology from the Insight lander suggests what could be described as a subsurface ocean in the same sense that Earth has one as well.
When lunar exploration promoters or advocates speak of the water there, they do not have icebergs or frozen lakes to trot out thus far. They usually point to the Aitken crater at the south pole and a trail into the dark as yet un-blazed. Yet without even an ice cube yet produced or retrieved, we have often often been urged to stampede off to the south pole and go mine. And if all else fails in persuasion, proponents argue that this lunar ice can be used to get somewhere else: Mars. Allowing astronauts to take a bath on the moon should suffice for a while after all that this effort will entail, wandering into a dark crater with the depth of the Grand Canyon.
I am not arguing against lunar exploration or outposts, but instead not to give up
on Mars too easily or prematurely, as though only one door can be opened at a time – or that it is an evident higher risk. Both at this point are nearly like blank canvases, yet distinctly different in their aspects.
IDK about living on MArs beyond small outposts, but a ready supply of water does imply rocket fuel and oxidizer, whether LH2/LOX or, using the Martian atmosphere and the Sabatier process, CH4/LOX. Mars, like Ceres, might be an important waystation in the solar system. These outposts would be the equivalent of fossil fuel production facilities, refineries, and “gas stations” that would increase our capabilities of exploring the solar system, and yes, exploiting its resources. If humans are to populate these outposts, then water is going to be a very important resource that reduces the habitation and supply costs.
Although most designs for Martian cities and bases are based on the aboveground terrestrial model, I think that a lot more thought needs to go into subsurface living, with designs that are more like the interiors of the Las Vegas “The Venetian” casino with a fake Venetian canal and fake sky ceiling. With technology, those skies could be digital projections of whatever one wanted – Mars, Earth, etc. Subsurface, the environment would be free of toxic dust and perchlorates, and well protected from all but the larger meteors. The facility would expand by grinding away at a subsurface glacier to produce the water, O2, and propellant to sustain the population and provide tradeable exports for the solar system economy.
Get a powerful enough magnetic field on the moon and you can generate your own water from the solar wind. The area collection power of the Moon allows many tons of water to be produced per day and a fair amount of heat power from hydrogen impact. It can also be used to reduce minerals to extract metals.
Sources of Water and Hydroxyl are Widespread on the Moon
September 16, 2024
Sept. 16, 2024, Tucson, Ariz. – A new analysis of maps of the near and far sides of the Moon shows that there are multiple sources of water and hydroxyl in the sunlit rocks and soils, including water-rich rocks excavated by meteor impacts at all latitudes.
“Future astronauts may be able to find water even near the equator by exploiting these water-rich areas. Previously, it was thought that only the polar region, and in particular, the deeply shadowed craters at the poles were where water could be found in abundance,” said Roger Clark, Senior Scientist at the Planetary Science Institute and lead author of “The Global Distribution of Water and Hydroxyl on the Moon as Seen by the Moon Mineralogy Mapper (M3)” that appears in the Planetary Science Journal. “Knowing where water is located not only helps to understand lunar geologic history, but also where astronauts may find water in the future.”
Clark and his research team, which includes PSI scientists Neil C. Pearson, Thomas B. McCord, Deborah L. Domingue, Amanda R. Hendrix and Georgiana Kramer, studied data from the Moon Mineralogy Mapper (M3) imaging spectrometer on the Chandrayaan-1 spacecraft, which orbited the Moon from 2008 to 2009, mapping water and hydroxyl on the near and far sides of the Moon in greater detail than ever before.
Full article here:
https://www.psi.edu/blog/sources-of-water-and-hydroxyl-are-widespread-on-the-moon/
The usefulness of this water depends on what they mean by “significant”. The rocks are no different than those on Earth, but we don’t heat them to extract water.
I could understand locating the impacts of water-rich objects, e.g. comets, and mining the subsurface for any remaining water, or even CC asteroids, but rocks?
I think we are talking about H2O contentment of 0.1 to 1 ppt based on this paper: High H2O Content in Pyroxenes of Residual Mantle Peridotites at a Mid Atlantic Ridge Segment, and these are rocks in the ocean.