
Scientists find likely source of methane on Mars - dnetesn
https://phys.org/news/2019-04-scientists-source-methane-mars.html
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ams6110
Methane is in the atmosphere of many planets and moons. I think I recall
reading that on Titan it rains liquid methane. Why is methane on Mars any more
remarkable than it is elsewhere?

Methane is an extremely simple molecule of carbon and hydrogen. Doesn't seem
too surprising to me that it's found all over the place.

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WhompingWindows
That simplicity you speak of means nothing inherently in chemistry, just
because it's a simple molecule doesn't mean it will be anywhere. In fact, the
sun's radiation degrades methane in the atmosphere, plus the Martian
atmosphere is very thin and thinning over time. How then to account for new
sources of methane observed by recent observations?

Microbes is one exciting option. Methanogenesis is the process of the
production of methane in microbes. It occurs in anaerobic respiration (i.e.
the microbes wouldn't need oxygen to make methane - check on Mars). It's the
final step in the consumption of old biomass. So, presumably, one could've had
microbes feeding on old organic material spewing methane. It would explain why
there are spikes in the methane levels, as the sun's radiation would have
degraded any old methane over time.

The other option is some sort of volcano or fissure in the planet's surface,
which would allow a geochemical source of methane, I don't know much about
that process though.

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craftyguy
> How then to account for new sources of methane observed by recent
> observations?

If you read the article, they explain where the methane is coming from.

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trentlott
> The most likely source was a sheet of frozen methane beneath a rock
> formation

While it is certainly pretty likely, it isn't necessarily known that this rock
is part of methane generation.

If it's coming from the ice directly, the ice sheet 'location' doesn't explain
whether the methane was from a biotic or abiotic source.

It probably eliminates the already-small likelihood that it is coming from
still-extant microorganisms, but it doesn't eliminate their possible
involvement in clathrate formation.

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okket
Article in the Guardian:
[https://www.theguardian.com/science/2019/apr/01/scientists-u...](https://www.theguardian.com/science/2019/apr/01/scientists-
uncover-potential-source-methane-mars)

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jayalpha
"If founded to be extensive, the methane it contains "could support a
sustained human presence" on Mars as a possible source of fuel for industrial
processes and a propellant for returning manned missions to Earth, he said."

How come? To use Energy you need an oxidant, preferably Oxygen. I googled the
atmosphere of Mars:

Carbon dioxide 95.32%

Nitrogen 1.9%

Argon 1.6%

Oxygen 0.13%

Carbon monoxide 0.08%

How are you going to use Methane as a fuel or propellant? 0.13% Oxygen looks
suspiciously low.

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stetrain
Water ice + electrolysis = Hydrogen (H2) and Oxygen (O2)

O2 and CH4 (methane) = rocket fuel

H2 + CO2(from atmosphere) + pressure + heat = CH4(more methane) + H2O
[https://en.wikipedia.org/wiki/Sabatier_reaction](https://en.wikipedia.org/wiki/Sabatier_reaction)

Basically some (SpaceX) have already been planning to use electrolysis of
water ice and atmospheric CO2 to create Methane and Oxygen to get rocket fuel
via the Sabatier reaction.

Finding existing Methane doesn't change a ton since the building blocks were
there anyway, but it may be less energy consuming and complex to mine/melt
methane directly and just deal with splitting water by electrolysis, which you
were going to have to do anyway to feed the Sabatier Reaction.

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jayalpha
Ok, then you assume that you have accessible water too. Still need the Energy
for electrolysis. But with solar or nuclear it may be possible.

~~~
elsonrodriguez
Most serious Mars return missions plan on simply bringing 1 ton of hydrogen
per every 10 tons of desired methane.

That way you can just rely on the martian atmosphere to produce your return
fuel instead of embarking on a entire mining expedition.

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everdev
tldr;

Something is actively producing methane in Mars but it's not necessary
microbial life.

> methane gas dissipates relatively quickly—within around 12 years on Earth

> they conducted two parallel experiments to determine the most likely source
> of methane on Mars to be an ice sheet east of Gale Crater—itself long
> assumed to be a dried up lake.

> The most likely source was a sheet of frozen methane beneath a rock
> formation, which the team believes periodically ejects the gas into the
> atmosphere.

> "Methane is important because it could be an indicator of microbial life,"
> he said. "But life is not required to explain these detections because
> methane can be produced by abiotic processes."

