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There are a series of questions on this site which are generally "Is there X on Mars?" "Are there sufficient Y to create Z on Mars?" And the answers are generally YES for the most part.

What is there that we don't expect to be able to find on Mars? I don't mean "we haven't found this yet, but we haven't really looked very hard", I mean more like "given the soil composition we have from Mars, Mars seems to be very poor in X, which is a pity because that means you can't do Y".

So, what is there that we would strictly have to import from off-planet to Mars given what we know currently?

Chris B. Behrens
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    Nitrogen and phosphorus are vital to life, and for growing plants in greenhouses which is popularly suggested, and are in low abundance on the Martian surface, as you yourself certainly have seen in the same publicly available tables and diagrams as I have. That is, those elements are harder to get, they do exist there like all elements do. I bet that phosphor is the bigger hurdle for greenhouses on Mars since nitrogen can be extracted from the Martian atmopshere. Don't need to bring much of it, though. – LocalFluff Feb 24 '17 at 17:35
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    If some elements were not found in the few samples analyzed by the rovers, we know nothing about their occurence at other places. Some rare elements on earth are found not everywhere but only at special locations. If there are natural mineral deposits on earth, we should expect them on Mars too. – Uwe Feb 24 '17 at 18:58
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    @Uwe: not that simple. Deposits may be formed by geological processes that do not exist on Mars. – MSalters Feb 24 '17 at 18:59
  • But if water was present on mars for a longer time, deposits may be formed by water. We do not know yet if the few samples with known composition are representative for the rest of the surface and deeper than a few centimeters. – Uwe Feb 24 '17 at 19:51
  • @LocalFluff very slightly related to "brought phosphorus". – uhoh Feb 24 '17 at 23:57
  • The answer is, in principle: "every element you'll need" minus "the few elements that you are billion-dollar-confident you'll easily find at your chosen landing site and can extract with the equipment you've brought". It's a question about planning based on incomplete knowledge, which is exactly what solar system exploration mission planning is like. The question is not "what elements do not exist on Mars" which doesn't have a good answer, it's really about mission planning with current incomplete knowledge. It's a good question! – uhoh Feb 25 '17 at 00:08
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    My perspective is that pretty much 100% is going to need to be brought on the first mission, then with in situ chemical plants, maybe 70% on the second, etc. on down. Then there's a critical, hopefully, low number that you can't get past without some real terraforming magic like crashing a comet into the planet or something. That's what I'm wondering about. I know it's speculation at this point, but that's okay. – Chris B. Behrens Feb 25 '17 at 18:43
  • If electrical power is available, there is always carbon, oxygen and nitrogen (and ok, Argon) from the atmosphere, which seems to be available everywhere on the surface, albeit thinner at the highest altitude. While technology to separate the CO2 and N2 in order to do something with it is not mature, these three elements are at least there for the "getting". – uhoh Feb 26 '17 at 06:16

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At an elemental level, Mars will contain at least to some degree all of the elements found on Earth, albeit at different proportions.

Mars is primarily igneous. Thus any kind of sedimentary and metamorphose minerals will not be found in any great abundance. Thus marble, slate, quartz, flint, clay, limestone, and others will be rare, if found at all. These could theoretically be manufactured, but aren't really required for most applications.

Just to give you an idea, the most important elements can be seen below, from Wikipedia. Mars has all of these, to some extent.

enter image description here

The one thing that I can't find is Helium. Nitrogen also appears much rarer then on Earth, as does most noble gases.

PearsonArtPhoto
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