
Life Exists in the Driest Desert on Earth. It Could Exist on Mars, Too - SirLJ
https://futurism.com/life-exists-driest-desert-earth-mars/
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allthenews
I do not understand the consistent assumption that life on other planets must
take a chemical and physical form similar to our own. Given the myriad of
unique chemical compositions and the seemingly infinite ways in which
information may be stored and propagated as molecular data, I feel it is
myopic to constrain our search for life to such a narrow chemistry.

Sure, I understand that given limited resources it is sensible to look for
what we know works, but I guess what I'm getting at is that articles which
infer potential for life on other planets based on earth-bound extremophiles
are probably not as substantial as they may seem.

I suppose time will tell.

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blkhawk
If you assume that physics works the same on other planets then carbon-based
life is simply the most likely simply from the chemistry we know about.
Speculation about say Si based life isn't new but nobody has come up with how
that type of organic chemistry might plausibly work.

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chii
but then, do chemists really know how carbon based life works really? if it
weren't for the living examples, wouldn't it be just as hard to work out how
proteins form and so on?

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dogma1138
It isn’t about knowing how carbon life works but understanding basic chemistry
which we do.

Carbon is the atomic floozy it will hook up with a lot of other elements and
can form relatively strong bonds, and it can have upto 4 bonds per carbon atom
nominally.

This makes carbon the star of its little own chemistry show.

Silicon is similar to carbon in this regard which is why it is in the same
column in the periodic table however it bonds with fewer elements and it’s
chem requires more energy and is often less stable.

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ethbro
This is what the grandparent question always skips over.

"Why not alternatives to organic life?"

Underestimates the fact that, as near as we can tell, building life from
organic molecules is _easier_ (and substantially so).

Given that life seems to be a relatively rare event sequence, and that organic
life is the easiest form we've been able to figure out from chemistry (ne
physics)... betting on another kind is a long shot.

Granted, maybe we've missed something obvious. Maybe our understanding is
critically flawed. But from everything we know right now, one can't just
handwave and say "Well, many kinds of life are possible."

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dogma1138
Indeed, currently there is no replacement for organic chemistry for life
because it seems that we can't find another combination that would be as
flexible and stable as carbon.

Silicon can replace carbon in a few scenarios but it isn't likely enough for
any plausible mechanism that would support life to be based on silicon alone.

This is why likely all life is carbon based, some of the other elements like
phosphors vs arsenic have more wiggle room but there is simply no "glue" other
than carbon and this is simply due to physics not lack of imagination or
knowledge.

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pmoriarty
Has there been any thought given to the possibility of life at the subatomic
level?

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dogma1138
Yes not possible not enough complexity or stability for that matter and the
energy levels required are well explosive the smaller you go the more energy
is needed since you essentially go form gravity (macro) to electroweak
(molecular and atomic) to the strong nuclear force (subatomic) and there is a
pretty big increase in magnitude of the forces that govern interactions
between each phase.

Heck even within the unified electroweak force there is a huge range e.g.
burning coal releases he energy in the stored covalent carbon bonds which are
tied by electromagnetism part of the electroweak force but if you start
breaking protons a part from neutrons which is the weak force you get a
nuclear bomb.

Life needs bonds that are cheap to create, cheap to break and ones that don’t
explode once you do break them.

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JohnJamesRambo
It is very likely life on earth evolved under more optimal conditions and then
adapted to drier and more extreme ones. Was Mars ever hospitable enough for
long enough for life to evolve is the question.

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thriftwy
Nope! First signs of life are found on Earth in very early minerals that
existed under extremely brutal conditions back then. They're also found in
oldest parta of crust that we have.

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blkhawk
well, AFAIK we still have no idea whats actually needed for life to form.

Also the conditions for life were better on mars in the past so its entirely
possible that life existed and kept on going on mars.

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joshbaptiste
"Why Alien Life Would be our Doom - The Great Filter" Great short video from
Kurzgesagt – In a Nutshell

[https://www.youtube.com/watch?v=UjtOGPJ0URM](https://www.youtube.com/watch?v=UjtOGPJ0URM)

~~~
Symmetry
Life arose very quickly on Earth after it cooled down. Photosynthesis took
longer and Eukaryotic life took longer still. Seeing a Martian protozoa that
evolved independently of Earth life would be scary. Bacterial mats around a
thermal vent not so much.

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

EDIT: It's also sort of scary to think that it took 4.5 billion years from the
first life for us to evolve, and it's only going to be another billion before
the growing sun sterilizes the Earth's surface.

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nukeop
Life _could_ exist anywhere, even in deep space, but apparently it doesn't.
You could probably interpret some behaviours of neutron stars as life.

I admire the human drive to solve the cosmic puzzle, find something bigger and
more meaningful than us, but so far it looks like there is only one place in
the Universe that has life. And even planets with relatively favourable
conditions like Mars are dry, lifeless husks devoid of any, even the simplest
lifeforms.

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ythn
Life almost definitely exists elsewhere, and this is coming from a religious
person. The number of star/planet combinations out there virtually guarantees
it mathematically. The problem is that space is too large and vast and the
speed of light too "slow" to be able to reliably "scan" the universe fast
enough to find life.

Two scenarios (at least):

1\. God exists and specifically seeded life on Earth.

Even if this is the case there is still no reason meteorites couldn't carry
microbes from Earth to Mars. It doesn't seem like God cares about quarantining
life to earth, seeing as we made it to the moon.

Also, why bother making a universe so mindbogglingly huge and vast only to put
life on a single planet? Makes more sense for God to seed countless planets
out there with life. And indeed there are a few verses in the Bible that imply
Earth is not God's only creation.

2\. God does not exist and life emerged naturally.

If this is the case then that means life can emerge naturally somewhere else
with identical conditions, and given the number of stars/planets/time elapsed,
this _seems_ like it could be a high probability (hard to know, though,
without understanding exactly how life emerges).

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llccbb
Big numbers don't "guarantee life", rather they make it "very unlikely there
isn't life". It is the same way that "an absence of evidence is not evidence
of an absence".

Secondly, it remains a challenge to categorize and define the envelope for
what is and isn't "life". We have a decent hold on "earth-like life" but it
will not be sufficient for all that might be encountered in due time (or
already exists unbeknownst to us). If you have ever defined an ontology you
know that it becomes more and more challenging to put definitions to the
universals as you climb up the ontology. At the top, the universal from which
all other universals inherit is very commonly left descriptionless.

Last, there are many alternative to the Christian One-God view that you
express (I am sure you are aware and chose to limit your points for brevity).
There are spiritual books that explain/propose/posit the universal disconnect
between the living conscious beings of Earth in this material plane and the
myriad of "beings" that exist in other higher dimensions/levels/shells.

~~~
ythn
"very unlikely there isn't life" == "very likely that there is life"

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zdky
As we keep sending probes to Mars, maybe some of the toughest forms of life
might be transported to Mars and become Martian before human does

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ohiovr
If any kind of life exists on Mars it would have to be unlike anything here.
Mars is bathed in peroxides and a whole spectrum of ionizing radation with
little to no magnetic field to protect it.
[https://www.ncbi.nlm.nih.gov/pubmed/11537371](https://www.ncbi.nlm.nih.gov/pubmed/11537371)

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simonh
There are many organisms that can tolerate those concentrations of peroxides,
and others that can tolerate the radiation exposure aside from the fact that a
few inches of soil provides fairly decent protection anyway.

From your link: "These results indicate that it is doubtful that the presence
of H2O2 alone on Mars would make the surface "self-sterilizing"."

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ohiovr
Sorry about that, this link from nature is a better angle to the problem (I
forgot about perchlorates on Mars).
[https://www.nature.com/articles/s41598-017-04910-3](https://www.nature.com/articles/s41598-017-04910-3)

looks pretty brutal up there

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readhn
At some point we will be asking ourselves - is it a good idea to bring those
alien life samples back to earth for analysis.....

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rbanffy
Even the driest desert on Earth has more atmosphere than Mars.

