It is the year something-something, and the Sol system has been colonized. The Sun is surrounded by a growing cloud of habitats, Venus is a veritable garden world, Jupiter is being fed mass from the sun so that it may one day turn into a brown dwarf, the Oort cloud is the new frontier, human lifespan is biologically indefinite, and Mars, despite being the least attractive candidate for terraforming, has turned into life-bearing world protected by a superconducting satellite that produces a magnetic field placed in the L1 Lagrange point.

It is a time of wonder and miracles.

Until it isn't.

Something caused the collapse of this civilization, and now only derelicts remain around the sun, the citizens of Earth, Venus and Mars had regressed back to a animalistic state while everyone else died, uploaded themselves into computer banks on Titan, or fled to the Oort cloud, and beyond.

Through out all this, the Satellite above Mars had persevered, keeping to its station like a sentinel of old with a shield of magnetic fields foreve-oh, never mind, got hit with a system wide Kessler syndrome event. Guess without Mars is doomed...Right?

Essentially, I'm wondering if it is possible to to have a a backup in case such an event where to occur. It's impractical to start up Mars's core so that's out. Perhaps having a mixture of genetically engineered life forms to create a specialized atmosphere more resistant to solar winds? If so, how? Are there other alternatives on the table? Do we have to go all Darwin IV on Mars?

Something to get out of the way.

Mars has been partially terraformed, there is a sea of liquid water, the air has been increased, though not to the level of earth's atmosphere and with, to Terrans at least, high levels of carbon dioxide. Plants and animals have adapted to these conditions.


First off, thank you to everyone who has commented so far it really helps.

Now, it appears that I may have been to unclear on what I was asking exactly. So! To remedy this, let me give a some more clarification than before.

  • The main point of debate is that there is need for a shielding due to the fact that atmospheric lose occurs over geological timescales. Thing is, the inhabitants of Mars in the setting would evolve into a post human species adapted to the red(?) planet (the bits of blue/violet and greenery ruin the image a bit) and that would take evolutionary timescales i.e. at least a millennia or more. Now, why have humans gone to such a state, that's a post for another time but suffice to say I have an interest in keeping the atmosphere intact for as long as possible, preferably as when the sun is big enough to non the Earth.

  • When I said life on Mars has 'adapted', what I meant to say was 'genetically engineered' then over the millennia grew accustomed to Mars. This is due to the fact Mars is in reality a very unattractive terraforming candidate for a carbon copy of Earth (Venus, once it was cooled down with mirrors, sped up with targeted comet strikes to produce a more 'normal' 24-ish day/night cycle, jump start it's magnetosphere, change the axial tilt slightly get some seasons in and funnel most of the CO2 and N out of the surface be used in the terraforming process, shipped to Mars, the space habitats or crushed into a sizeable diamond moon with bits of Mercury sprinkled in; the end result is a good candidate for colonizing, though bit on the tropical side;)), thus Mars was terraformed till it was 'good enough', meaning the deepest the deepest body of water is around 1.5-2 kilometers deep, the atmosphere was thickened though not Earths 14.7 psi of atmospheric pressure but enough to cause storms of some concern, so around 9-10 psi if my horrible knowledge of atmospheric science estimation is right. The life there, along with the human population, was genetically modified to handle lower pressures and the much higher CO2 levels (though the high CO2 levels would give an excuse as to why the colonists turned feral, though not a good one), and have overall better radiation repair, though that was added as a after thought following bureaucracy and the vocal minority calling "just in case!". However, life on Mars can live in more extreme conditions, though I would like to keep the conditions as stated above for as long as possible.

  • The question I'm asking is there a any way to keep such an atmosphere with without machinery and instead through some biological process, either naturally evolving by coincidence or through genetic engineering?

Thank you.

  • 8
    $\begingroup$ u do your numbers Mars presently loses about 100 grams (a quarter of a pound) of atmosphere every second, which is about 3000t per year. would say that the number will not depend that much on the density of air at the surface, but one can multiply it by a 100, current atmosphere mass about 2.5e13t, soo if pressure on the surface would be 100kpa, to lose 1 percent of it it will take about 100 million years. plenty of time to die out or crawl back to the technology and space age. $\endgroup$
    – MolbOrg
    Commented Jan 17, 2021 at 22:58
  • 3
    $\begingroup$ It's a non-problem. The lack of a magnetic field leads to the loss of atmosphere over geological time. Not an issue on human time-scales, not even an issue on historical time-scales. There are only 15,000 years between the invention of agriculture and our present day... and at least one million years is needed for the loss of atmosphere to become measurable. $\endgroup$
    – AlexP
    Commented Jan 17, 2021 at 23:23
  • 3
    $\begingroup$ As MolbOrg points out, atmospheric loss is something to be concerned about on geological timescales. Also, an atmosphere with the same surface pressure as Earth's will be far deeper than Earth's, making it a very effective radiation shield. Mars just doesn't need a magnetic field. Your "garden world" Venus is in trouble though, since even if you somehow deal with its hellish atmosphere, it'll be reliant on some form of orbital shades and artificial light/heat sources to make it habitable. As support systems fail, it's going to start roasting each 2-month day and freezing each 2-month night. $\endgroup$ Commented Jan 17, 2021 at 23:23
  • $\begingroup$ You seem to be thinking that the only effect of no magnetosphere is that the solar wind blows the atmosphere away. You seem to be forgetting that the solar wind itself is dangerous and is full of radiation. $\endgroup$
    – DKNguyen
    Commented Jan 18, 2021 at 16:05
  • $\begingroup$ @DKNguyen an atmosphere will block radiation, especially if you pile up enough to have ~1 atm of surface pressure in Mars gravity. Even the existing atmosphere provides a lot of shielding: jpl.nasa.gov/images/estimated-radiation-dosage-on-mars $\endgroup$ Commented Jan 18, 2021 at 17:01

3 Answers 3


/Plants and animals have adapted to these conditions/

They adapt further! The difference between low atmospheric pressure and progressively lower atmospheric pressure is a lot less than the difference between living underwater in an ocean and living in a desert. Earth life pulled off the latter feat. Over time your Mars creatures can pull off the former.

I could imagine photosynthesizers with robust waxy layers to limit water loss into the low atmospheric pressure. Perhaps these creatures hang on to the oxygen they form in their tissues just like they hang on to the sugars, so they can use both for subsequent metabolism rather than rely on atmospheric O2.

This would be fine story telling. There would be the native Martian flora and fauna which in some places would be dying out. Then there are the adapted forms which are spreading - similar to what was there before but more and different.

Don't forget the adapted Earth life which has formed symbioses with indigenous Mars life! Could that symbiosis swing the other way? Remember the Mars life did this whole "lost the atmosphere" thing once before, and got through it.

  • $\begingroup$ Thanks for the bounty @Seraphim! $\endgroup$
    – Willk
    Commented Jan 27, 2021 at 3:18

Building upon MolbOrg's comment, it seems you just have to produce 100g of athmospheric content to counter the effect of solar winds on the athmosphere.

So the old civilisation could have created huge machines that produce gases from the soil. For example on the poles there could be solid oxide electrolysis process installed that turns the water into hydrogen and oxygen. Like the MOXIE prototype.

Also silica has been found on mars. Which reacts partly to water, when combined with hydrofluoric acid.

Or basically from any other material the old civilisations brought up there. Powered by solar or nuclear fusion, since they seemed to have been pretty advanced.

  • 2
    $\begingroup$ Silica can't be turned into water with anything short of nuclear transmutation, and you don't need hydrofluoric acid to get the oxygen out. And MOXIE's for electrolyzing carbon dioxide...you don't need a fancy high temperature solid oxide electrolyte to electrolyze water. $\endgroup$ Commented Jan 18, 2021 at 0:19
  • $\begingroup$ @ChristopherJamesHuff Silica is silicon dioxide. And SiO2 + 6 HF -> H2SiF6 + 2 H20 Sure, you can do something less sophisticated to electrolyze water. $\endgroup$
    – r3dapple
    Commented Jan 18, 2021 at 9:59
  • $\begingroup$ That's not "turning silica into water", that's producing some water as one product of reacting it with hydrofluoric acid. Where are you going to get that? Fluorine is extremely scarce and itself has to be separated from mineral fluorides, which is even more energy intensive than splitting oxygen from oxides. Worse, the only local source of hydrogen is the existing water ice, making this whole reaction a dead end. $\endgroup$ Commented Jan 18, 2021 at 15:17
  • $\begingroup$ @ChristopherJamesHuff You are right. I changed the wording. Well the hydrofluric acid could have been brought there in large storage tanks from the old civilisation. Since they terraformed Mars so substantially that plantlife and animals can inhabit it, that doesnt seem like too far of a stretch. $\endgroup$
    – r3dapple
    Commented Jan 18, 2021 at 15:54
  • $\begingroup$ There's still the issue of fluorine being very scarce, and the fluorine atom in a HF molecule weighs 19 times as much as the hydrogen, more than a whole H2O molecule. You need to transport hydrogen to Mars and split oxygen out of rock...HF is a terrible way to do the former and is unnecessary for doing the latter. You could just import elemental hydrogen to combine with the oxygen to make water, and electrolyze molten rock directly to produce free oxygen (look up molten oxide electrolysis). Then you "just" need to import a few quintillion tons of nitrogen to get an Earthlike atmosphere... $\endgroup$ Commented Jan 18, 2021 at 16:54

what you could have a hyper bacteria, which is very light, and floats in the atmosphere, they feed of light, heat, radiation, etc. whichever you want, they are in such numbers that they block solar winds, there could have other bacteria to break down some of the surface to make more of an atmosphere, caves would also be an alternative, just make your fauna be underground mostly, and a failsafe that absorbed the "atmosphere" it already had, and bring it into a refuge, plants get to this tank, and form an ecosystem inside the refuge, you let some survive inside, as well as animals, and close any gas exit, the plant also has a piece for the collection of sunlight, waxy layer to reduce water loss, and possibly get more energy from the sun, and a mix of chemosynthesis, (you could also have a machine for the use of solar winds for pure energy, and the plants adapt thanks to genetic modification to transform more kinds of energy for them to use it)

having a solar wind resistant super forest, which grows a shield, so it creates a cave system, mycelial networks work as a part of this ecosystem, the mycelium here was modified to be much better, and smarter, it grows inside the solar shield, and transforms heat from the sun into energy which is spread through the plants, eolic type energy is used, which can be mostly unaffected material as Martian winds are generally stronger than earth's

the sea can have a new roof of materials, on the surface protecting t from evaporating, also, heat can be turned into energy by the plants, as well as light hitting the surface, the water would be highly oxygenated, creature transform part of the soil on cave roofs into food, and their poop is eaten, by plants, fish etc. they could survive for some time,

sorry for any clutter, I'm a bit tired

  • $\begingroup$ The solar wind doesn't penetrate into the atmosphere, it gets deflected way up at the upper reaches of the ionosphere. You'd be partially shielded from it even in low orbit, even though Mars doesn't have a global magnetic field any more (lasp.colorado.edu/~brain/images/induced_more.jpg). You mainly have to worry about UV, and an oxygenated atmosphere will form an ozone layer under the right conditions. $\endgroup$ Commented Jan 22, 2021 at 16:04

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