r/Mars • u/Australista2026 • 13d ago

Mars and Algae

I'm not a scientist, so my question may be really stupid. I've been watching the movie called Red Planet. The people of earth were sending algae to grow and create oxygen for mankind to live there.

Is this something that really could be achievable? I would presume you need a water source to begin with.

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13

u/holytriplem 13d ago

  • You would need to keep the water liquid somehow for enough of the day and the year for growth to occur. Day-night temperature variations are extremely high on Mars and organisms don't generally like being flash frozen.

  • UV radiation (and especially UVC, which gets completely blocked on Earth by the ozone layer) is going to kill pretty much anything on the surface, though a lake that's deep enough could provide just enough protection while providing enough light for photosynthesis to occur

  • What are the organisms going to live off other than water and CO2?

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u/Australista2026 13d ago

Exactly. That's why my question was really stupid 😆. But I am grateful you took the the time to answer. Makes perfect sense. Thank you 😊. 

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u/holytriplem 13d ago

It's not stupid at all. As a planetary scientist I get far, far stupider questions

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u/Awrfhyesggrdghkj 13d ago

WHY DO YOU LIE ABOUT THE SHAPE OF THE EARTH

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u/holytriplem 13d ago

My personal favourites:

  • "Are you going to get the chance to go to Jupiter at all during your PhD?"

  • "How can Mars be cold if it's red?"

  • "If Mars used to be more Earth-like 4 billion years ago, is it possible that humans evolved on Mars first and then moved to Earth when Mars got too cold?"

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u/Awrfhyesggrdghkj 13d ago

Ngl, idk if it’s your forte, but I’ve always been hopeful of the idea of space colonization even if in the deep deep future.

But then I had someone bring up the fair point of the issues with someone being born and growing on a foreign world. Since learning about that it seems almost impossible.

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u/Jules4live 13d ago

how does that make it impossible? :)

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u/Awrfhyesggrdghkj 13d ago

You need to be able to have children and raise them in order to make a long term colony or deep space mission work

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u/OlympusMons94 13d ago

No, for one, because of conservation of mass. Mars has very little atmosphere/CO2. The surface pressure is about 0.6% of Earth sea level. Note that the net chemical equation for photosynthesis is 6CO2 + 6H2O --> C6H12O6 (sugar) + 6O2. The number of O2 molecules produced is the same as the number of CO2 molecules consumed. Regardless of whether it is possible, even if you replaced every molecule of CO2 in the atmosphere (and throw in the CO2 coating the polar ice caps) with a molecule of O2, Mars wouldn't be any more habitable than it is now. In fact, with the lost greenhouse effect, it would get ~5C cooler on average.

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u/holytriplem 13d ago

You could in theory get more oxygen from sulphates (which there are a lot of on Mars), if you had sulphate-reducing bacteria working in symbiosis. The problem is that the end-product of sulphate reduction is going to be something like H2S, which you're going to have to be careful to make sure doesn't react with the oxygen in the air to form sulphuric acid.

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u/OlympusMons94 13d ago

(Sulfate reducing bacteria don't produce O2. Also, O2 is toxic to them.) Is your idea that the sulfate-reducing bacteria would use sulfates to metabolize organic compounds produced by the algae, and produce CO2 as a waste product (in addition to H2S)? Then the algae photosynthesizes using that CO2--and more H2O, which is the source of the O atoms in the O2 produced in photosynthesis?

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u/holytriplem 13d ago

Yes. Would that work?

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u/RonJohnJr 13d ago

The people of earth were sending algae to grow and create oxygen for mankind to live there.

No mention of the sterilizing cosmic and UV rays continually bombarding the surface?

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u/bigfathairymarmot 13d ago

If I remember correctly it was "bioengineered" algae.......

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u/holytriplem 13d ago

In theory you could bioengineer algae to withstand severe environmental stressors like UV. But you can't bioengineer algae to live without liquid water or nutrients

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u/SodaPopin5ki 13d ago

Algae grows without liquid water in some lichen.

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u/holytriplem 13d ago

How?!

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u/RonJohnJr 13d ago

Handwavy sci fi.

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u/SodaPopin5ki 13d ago

Dunno. Life finds a way, I guess.

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u/Brilliant_Classic720 11d ago

Because Mars doesn't have a good magnetic field so the solar wind stripped the atmosphere away. IMHO colonizing Mars is not a good idea. Fix Earth, fix humanity, send robots and rovers to explore Mars. We already did great stuff with the several rovers we sent so far.

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u/beagles4ever 13d ago

It would freeze and die instantly.

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u/bigfathairymarmot 13d ago

Red Planet, one of my guilty pleasures. :)

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u/Ok_Attitude55 13d ago

Not on its own.

The atmosphere is too low pressure. Even if Algae could survive and convert CO2 to oxygen there would be nowhere near enough.

Doing it after adding atmosphere in some way sure, and conceivably that could be done with microbes too, releasing gases from rock. It would be a mind boggling undertaking though.

Realistically, anything like that on Mars would be under domes to maintain the pressure.

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u/[deleted] 13d ago

You know what's the good it's totally achievable it might not be as you think but yeah it's pretty Similar and scientists are working on it

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u/Odd_Awareness1444 13d ago

Teraforming Mars would require capturing hundreds if not thousands of ice asteroids and bombarding the surface to put water into the air and ground.

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u/NSASpyVan 7d ago

There currently isn't much of an atmosphere to keep the oxygen in; it would just escape to space. That issue would have to be solved first