
Mars likely to have enough oxygen to support life: study - daegloe
https://phys.org/news/2018-10-mars-oxygen-life.html
======
coldnose
AFAIK, the ability to tolerate oxygen is an advanced property of terrestrial
life — the simplest, oldest life forms were totally unable to survive in the
presence of oxygen.

~~~
gizmo686
The Great Oxygenation Event [0]. Arguably the planet's first mass extinction.

To say that nothing we have done to the planet is as bad for the environment
as the Great Oxygenation Event would be to pat ourselves on the back for not
literally poisoning the atmosphere.

[0]
[https://en.wikipedia.org/wiki/Great_Oxygenation_Event](https://en.wikipedia.org/wiki/Great_Oxygenation_Event)

~~~
cbkeller
Geologist here. Yeah, there are a few places you can find microbial survivors
of the GOE:

[https://en.wikipedia.org/wiki/Green_sulfur_bacteria](https://en.wikipedia.org/wiki/Green_sulfur_bacteria)

[https://en.wikipedia.org/wiki/Purple_sulfur_bacteria](https://en.wikipedia.org/wiki/Purple_sulfur_bacteria)

Obligate anaerobic photoautotrophs: they photosynthesize, and need light to
survive, but don't produce (and are killed by) O2. Unfortunately for them,
post-GOE, there aren't many habitats that are anoxic but still have much
light!

There's at least one clade of "green sulfur bacteria" that apparently lives
off the basically-invisible glow from a black smoker at a mid-ocean ridge:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1166624/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1166624/)

fascinating stuff!

~~~
Balgair
PBS Eons is a great youtube channel on Earth's biological history. It's very
well done stuff. Their 'Purple Earth' video is a good layman's intro to some
of the per-oxygenation earth: [https://www.youtube.com/watch?v=IIA-
k_bBcL0](https://www.youtube.com/watch?v=IIA-k_bBcL0)

The early biological history of Earth has a few 'Colored Earth' phases: Red-
Purple-Green-White-Blue(hypothetically).

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Sniffnoy
Mightn't this indicate that life on Mars is _less_ , not more, likely than we
thought? Respiration is complicated, so I would expect any life that might
have existed on Mars to be anaerobic. If there's actually enough oxygen to
support aerobic life, that doesn't bode well for any anaerobic life, does it?

~~~
cbkeller
Geologist here. I would tend to agree, considering that present-day oxidizing
conditions on mars are generally thought to be due to photolysis and hydrogen
loss, not life/photosynthesis, e.g.:
[https://www.liebertpub.com/doi/abs/10.1089/ast.2013.0999](https://www.liebertpub.com/doi/abs/10.1089/ast.2013.0999)
[https://www.sciencedirect.com/science/article/pii/S001910350...](https://www.sciencedirect.com/science/article/pii/S0019103503001702)

Heck, Mars is so oxidized it has soils that are 0.5% perchorate:
[https://en.wikipedia.org/wiki/Perchlorate#On_Mars](https://en.wikipedia.org/wiki/Perchlorate#On_Mars)
and that stuff's so oxidizing it's not even common on Earth outside of
fireworks and rocket propellants

~~~
richardknop
What are the current thoughts on what caused oceans on Mars to disappear (with
some remainder concentrating in ice caps)? Was it some impact of a really big
meteor/comet? It is accepted that Mars used to have liquid water oceans and
rivers in the past, correct? You can see geological remains of rivers and
oceans, for example, quite clearly on Mars.

~~~
adrianN
Mars gravitiy is not strong enough causing it to very slowly lose gases to the
solar wind. Water vapor included.

~~~
richardknop
So how can we Terraform Mars to make it like Earth then? It seems impossible
due to the gravity being so small. Even if we melt ice caps and get liquid
water running again, it will slowly evaporate to space? How could a colony on
Mars then be self sustaining with this problem?

~~~
Symmetry
As the other reply mentioned, this is a millions of years sort of problem. But
there are two straightforward solutions. First, in the new atmosphere make
sure there's enough oxygen to breath so that an ozone layer forms. That's
something we want to do anyways. Also, give Mars a magnetic field. That's a
stupendously large but straightforward engineering problem, sort of like
terraforming is in the first place but smaller.

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fuscy
I never understood why colonizing Mars is needed.

Even if a meteorite hits Earth or Yellowstone erupts, Earth would be more
"hospitable" to life than any other planet in our solar system because Earth
has a lot of resources that are right under our noses: breathable atmosphere,
radiation shielding, easily mined metals and organic matter.

It's much easier to build and maintain a bio-dome in the Sahara desert, Arctic
region, Cheyenne mountains or underwater than on Mars.

Earth at it's worst is much better than anywhere else in our solar system.

~~~
alex_duf
>I never understood why colonizing Mars is needed.

Personally I see quite a few positive things behind colonising Mars.

I think it's not about having a "backup", it's not about resources (or in a
really long time) it's about the challenge.

If we can put our best engineers to solve how we re-use and recycle water, how
we grow crops in extreme condition, how to control the O2 CO2 cycle (at a
larger scale than on the space station), how to engineer a space craft that
survive such harsh conditions we will end up with:

\- technology to help our crops on earth

\- technology to help with our water crisis

\- technology to build sturdier structures

\- international collaboration, that usually keep engineers from working on
mass weaponry (The USA/Russian space program is actually motivated by exactly
that: keeping the rocket scientists busy instead of working on ICBMs)

Mars just happen to be a goal silly enough that we'll get interesting
discoveries and advances that I can't even foresee.

Another way to keep engineers busy and force international collaboration is to
have a common threat. For that I believe the asteroid threat is both a real
enough threat and a good subject to work collaboratively.

~~~
da_chicken
It's kind of like learning how to program when you don't have any task to
complete. Especially for a data store of some kind. If you've ever tried to
learn SQL, even if you've got an example database, you'll find it's incredibly
difficult not because the syntax is all that difficult or the logic is
particularly daunting. No, you'll find it's difficult because _you don 't have
any questions to answer_. You'll feel, "Okay, now what?" When you try to make
up a question to answer, it's difficult to tell if you're answering the
question correctly. You need the focus that a real problem gives you. You need
the guidance that understanding what the data means gives you (or someone
else) to know if your answer is right or wrong.

It's easy to see what a tool is designed to do. It's very difficult to see
what a tool can be used for and why you might want to use it that way, let
alone when you might want to deviate from that or find alternatives due to
limitations or new requirements. Or when you might need entirely different
tools.

We learn best when we're working on a problem. Just like going to the moon
required solving a lot of problems which led to major advancements in the 20th
century, going to Mars, colonizing Mars, and colonizing the moon have even
more challenges.

Goals give research and development a clear purpose beyond, "I dunno, make
something people want that we can sell."

~~~
squish78
I'm saving this answer. Love it.

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onemoresoop
Setting a moon base would teach us things quite a lot faster than going to
Mars because of the distance and close proximity to earth. The moon is
different than Mars, i know, but Mars would come up next after this. I think
space travel would be much easier if started from a moon base due to the low
gravity. A disaster on Mars would delay this project by a few centuries. Let's
make small firm steps.

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ravron
But it may not have enough carbon dioxide:

[http://lasp.colorado.edu/home/maven/files/2018/08/Inventory-...](http://lasp.colorado.edu/home/maven/files/2018/08/Inventory-
of-CO2-available-for-terraforming-Mars.pdf)

~~~
sigstoat
there are other, significantly more effective, greenhouse gases.

~~~
bobm_kite9
I thought the absence of a magnetosphere would mean that any atmosphere would
be stripped away by solar radiation anyway?

~~~
adrianN
Over millions of years.

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jacobwilliamroy
Things I know about Mars:

>No oceans

>No plants

>No phytoplankton

>Massive planetwide dust storms lasting several months

>Average surface temperatures at or below freezing

>Space suit required

Things I know about Earth:

>Drinking water falls from the sky

>Food grows on trees

>Breathable atmosphere

>Clothing optional in most areas

>I can feel actual sunlight on my face every day

~~~
njarboe
Things I know about Mars:

No established legal or social framework.

Things I know about Earth:

Probability of finding a place to be left alone with a small group of like
minded people. 0

A certain type of person is interested in living a life where they have a
large amount of control over the political and social systems they live with.
The American frontier was an ideal place for such people to move to. Many took
advantage of the opportunity. This frontier is now closed.

Off Earth is the only viable place for similar frontier to exist and Mars is
the best place. It has a ~24hr day, decent gravity(0.38g), Ok solar radiation,
H,C,O,N readily available on the surface, and possible terraforming to a open-
air livable planet.

~~~
ElBarto
The upper atmosphere of Venus is actually the closest to Earth conditions we
have in the solar system.

Just float around in an airtight habitat. Gravity is the same as on Earth,
pressure is the same, temperature is 25C. You literally only need to be
airtight to keep the noxious atmosphere at bay.

~~~
patricklouys
But where do you get additional resources?

~~~
coldtea
By closed-system agriculture and farming and so on.

Why, where would you get them on Mars?

~~~
richardknop
It's easier and much more efficient to get resources such as raw materials and
metals from the ground. Being in the air without option of landing means you
are completely dependent on import of raw materials to repair/expand your
habitat. Very inefficient as well as not economical.

It might be cheaper to get to Venus than to Mars but on Mars you can actually
start mining and building factories on the ground. At some point, it becomes
much cheaper and more economical. It's just the initial hurdle of getting
there with enough stuff and people to start a colony which can self sustain
itself and grow.

Once you have brought enough initial stuff to Mars, you get to a point where
you can start extracting materials from the ground and free up all the cargo
in the ships for just people and perhaps some special items you still cannot
manufacture on Mars. But majority of cargo space is freed up.

~~~
coldtea
> _It 's easier and much more efficient to get resources such as raw materials
> and metals from the ground. Being in the air without option of landing means
> you are completely dependent on import of raw materials to repair/expand
> your habitat. Very inefficient as well as not economical._

Assuming you overcome all the other difficulties and have a colony on Venus'
skies, what prevents you from having ships that can go to the ground, get
stuff, and come back?

~~~
richardknop
It was my understanding that the surface of Venus is infernal, with super high
temperature (hotter than Mercury which is closer to sun), rains of sulphuric
acid and very high density. Building machines capable of landing there and
being able to return seems like a tall order.

Since for humans it is inconceivable to go down to Venus ground (they'd die
immediately from the heat), mining materials and then lifting again and
returning back to the habitat in the upper atmosphere, then you'd need to
automate the whole process.

The automated machine would have to be incredibly durable to survive the
hellish ground environment and be able to fly away again. Also drones that
would do the mining work would need to be made from incredibly strong
materials. There's a reason we only send suicide probes to Venus that live
maybe for couple hours before dying.

Also for humans, cold temperature is easier to survive compared to very high
temperature. We can generate heating for astronauts (batteries in space suites
can generate heat, we can recharge batteries from solar panels brought by the
mothership or on previous automated mission, or from RTG). I'm not sure how
would a cooling system for astronauts to be able to survive in 700 degrees
Celsius for longer than few minutes even work.

~~~
v_lisivka
High temperature and strong winds on surface can be beneficial to machinery.
You can fight with them or you can use their help to reach goal. IMHO, an AI
system and physical simulator can develop some pretty interesting ideas how to
use these conditions for efficient mining and transportation.

First idea: use wind to power instruments directly via mechanical or pneumatic
link.

Second idea: use silicon to produce machinery and tools.

Third idea: high temperature means it's much easier to melt ores, some metal
can be collected directly in liquid form.

Fourth idea: air balloons should be very inexpensive way of transport ores to
top of atmosphere, where they can be picked up by colonists.

Fifth idea: use mechanical computers to control equipment. It's not so hard to
create surfaces which will perform calculations required to navigation,
landing, mining, and floating back to surface. Mechanical computers can be
crawled out of silicon, with liquid metal for transportation of messages, and
vibration can be used to power such computer. 100kHz vibration is easy to
reach. At 100kHz, it will be equal to 1kHz electronic computer.

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MeteorMarc
Can anybody explain: the article mentions 0.14% of oxygen in a low pressure
atmosphere to be insufficient for aerobic life. Where does the higher oxygen
concentration (mole/m3) in subsurface brine come from? Obviously it is not in
equilibrium with the atmospheric concentration. Is it non-equilibrium due to
historic circumstances? Is it an equilibrium with surrounding rocks? Do rocks
outgas oxygen?

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User23
The only reason the Earth has enough oxygen to "support life" is because life
produced it as a waste product.
[https://en.wikipedia.org/wiki/Great_Oxygenation_Event](https://en.wikipedia.org/wiki/Great_Oxygenation_Event)

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StreamBright
Oxygen yes, magnetic field no. Without magnetic field you can't really live on
a planet.

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known
[https://en.wikipedia.org/wiki/Future_of_Earth](https://en.wikipedia.org/wiki/Future_of_Earth)

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_pRwn_
the main problems of mars are not oxygen but the missing magnetosphere and
associated high levels of radiation

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alfiedotwtf
Nobody tell this to Cohagen

