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I would like to know how similar Mars water is to Earth water. Can we survive on Mars with Martian water without any major health issues etc?

PearsonArtPhoto
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goodyzain
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  • There has been an edit suggested: "how long would we survive on mars with the water?" This changes the question, does not fit with the existing answers, and ought to be asked as a separate question. – DrSheldon Apr 28 '21 at 04:57

2 Answers2

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Fundamentally, water is water. In its purest form, it is the same anywhere, except perhaps for the isotopes. However, one of the wonderful things about water is the fact that it's a good solvent, and in fact has many things in it that aren't water. For instance, one could not survive off of ocean water: we humans require fresh water.

The one potential difference is in the isotope of the water. This is a rather complex concept, basically some water is heavier than other water, despite having the same chemistry. It turns out that Mars has a higher concentration of heavy water than Earth does. However, it is still within reason to us humans to use. It would make fusion easier, but that's another matter entirely.

The water that was discovered on Mars recently is unique. It is believed to be a very salty water; in its natural form humans could not drink it. However, it can go through a desalinization process, where the salt is removed, and in theory it should be drinkable. Basically, the water needs to evaporate, then re-cool.

As was said in the press conference, the best source of water for astronauts would be in the ice caps, which are similar to Earth's ice caps: frozen water on the surface, which would simply require melting to use, along with a small purification process.

Bottom line, there is water on Mars, and through some purification process, it can be made for human consumption.

PearsonArtPhoto
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  • the mars water is almost same as earths..then why there are no life(why so much difficulty for us to find life on mars :) )...?? – goodyzain Sep 29 '15 at 11:26
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    There isn't much life in the dead sea, and Mars water is much saltier – PearsonArtPhoto Sep 29 '15 at 11:31
  • Mars is very dry, cold, and has very little atmosphere. Any life would have to be extremely hardy, being able to tolerate huge differences in temperature with very little nutrition, all the while being bombarded by high radiation. If life is on mars there probably won't be much of it, and it will be microscopic, which is why it is hard to find. – GdD Sep 29 '15 at 12:15
  • Fundamentally, water is water. Well sure, but I wouldn't really drink highly deuterated water, and it's still just water. – TildalWave Sep 29 '15 at 13:49
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    That kind of water's probably okay, I just wouldn't want any Tritiated water. Still, I'm sure the isotopes are similar to that of Earth's, but I'll look into it. – PearsonArtPhoto Sep 29 '15 at 14:05
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    @TildalWave "I wouldn't really drink highly deuterated water" Why not? It is not radioactive, and despite being slightly more dense, it should have the same chemical properties as non-deuterium based water. – Andrew Thompson Sep 29 '15 at 14:06
  • @AndrewThompson Sure, go ahead. Like I said, I wouldn't. But I've seen people do crazier things, so it wouldn't really surprise me if someone would. – TildalWave Sep 29 '15 at 14:15
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    Earths ocean water can also go through a desalinization process to be drinkable. Currently 1% of the Earths people are dependent on manual/human desalinization for survival (per wikipedia) ultimately the other 99% of Earth people are dependent on naturally desalinated water for survival – James Jenkins Sep 29 '15 at 14:22
  • @TildalWave "Like I said, I wouldn't." Like I asked.. "Why not?". From the little I've heard, the best I could put it down to is 'fear of the unknown', but do you have some more specific reason for not wanting to drink heavy water? ..weight gain? ..becoming physically more dense and its effects on muscles and skeleton? And another question while I'm at it: If someone invited you along on a mission to Mars where your only water for six months would be heavy water, would you refuse to go? – Andrew Thompson Sep 29 '15 at 14:23
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    @AndrewThompson See Heavy water#Effect on biological systems, including toxicity: Mammals, such as rats, given heavy water to drink die after a week, at a time when their body water approaches about 50% deuteration. Hydrogen bonds work differently. – gerrit Sep 29 '15 at 14:35
  • @gerrit Huh.. I missed that from the article. Yes I get the caution now. No more drinking heavy water for me, I'll just save it for the H-bomb. ;) – Andrew Thompson Sep 29 '15 at 14:46
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    "Basically, the water needs to evaporate, then re-cool" is not the whole story. That's usually using way too much energy and there are alternatives like reverse osmosis to clean water. – Josef Sep 29 '15 at 14:48
  • Evaporating water on Mars is pretty easy, expose it to a vacuum, and it'll evaporate. But yes, that's the idea. – PearsonArtPhoto Sep 29 '15 at 14:54
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    @AndrewThompson Wikipedia doesn't tell the whole reason why it's toxic. The chemical properties themselves don't change between isotopes, but in the case of hydrogen the mass difference is so big that it matters. Deuterium is about double as heavy as regular hydrogen. This means doubled inertia for each hydrogen atom in heavy water, which causes the different behaviour in hydrogen bonds. – cg909 Sep 29 '15 at 23:57
  • @gerrit At the concentration levels required for "toxicity". I would be much more worried about what neutron radiation source generated the highly Deuterated Water...The landscape around the water should look like a disco orgy crime scene. – Aron Sep 30 '15 at 10:15
  • If Mars water is heavily deuterated, it will probably be due to the lighter isotopes having been preferentially lost at the top of the atmosphere, rather than neutron irradiation. – Steve Linton Jan 27 '19 at 17:47
  • What about isotopes of oxygen? – Anthony X Jan 27 '19 at 19:21
  • @AnthonyX This paper https://www.jstor.org/stable/1742562?seq=1#page_scan_tab_contents suggests that there is not much difference – Steve Linton Jan 28 '19 at 07:38
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This discussion on quora talks about deuterium abundance on Mars:

Deuterium occurs naturally on Earth in water as 1 in 6,400 hydrogen atoms or 1 part in 3,200 by weight. On Mars it is one deuterium for every 1,284 hydrogens.

So high enough to be noticeable in a lab (for example Mars water is about 700 ppm denser than Earth water under equivalent conditions) but not enough to be relevant for drinking.

Steve Linton
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  • This is an important point, thanks for the numerical value. It would be good to have some sense of human toxicity. Wiki suggests 25% deuterium is toxic, but no safe level stated. Humans on Earth said to have 1.1g D, equivalent to 5.5g heavy water; Mars would give 4.4g D, equivalent to 22g heavy water. – Bit Chaser Jan 27 '19 at 21:04