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Enceladus & Europa: profusely populated with microbial life and The 3 Monkeys at NASA
#34
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https://news.asu.edu/20210517-deep-water...esium-rich

Deep water on Neptune and Uranus may be magnesium-rich

In a new study recently published in Nature Astronomy,
a team of scientists re-created the temperature and pressure
of the interiors of Neptune and Uranus in the lab,
and in so doing have gained a greater understanding of the chemistry of these planets’ deep water layers.
Their findings also provide clues to the composition of oceans on water-rich exoplanets outside our solar system.

“Ice giants and some exoplanets have very deep water layers,
unlike terrestrial planets.
We proposed the possibility of an atomic-scale mixing of two of the planet-building materials,
(water and rock) in the interiors of ice giants.”


To mimic the conditions of the deep water layers on Neptune and Uranus in the lab,
the team first immersed typical rock-forming minerals,
olivine and ferropericlase,
in water and compressed Whip the sample in a diamond-anvil to very high pressures Whip 

Then, to monitor the reaction between the minerals and water,
they took X-ray measurements while a laser heated the sample to a high temperature.

The resulting chemical reaction led to high concentrations of magnesium in the water.

Based on these findings,
the team concluded that oceans on water-rich planets,
may not have the same chemical properties as the Earth’s ocean,
and high pressure would make those oceans rich in magnesium.


“We found that magnesium becomes much more soluble in water at high pressures.
In fact, magnesium may become as soluble, Hmm2
in the water layers of Uranus and Neptune as salt is in Earth’s ocean,”
said study co-author Sang-Heon Dan Shim of Arizona State University’s School of Earth and Space Exploration. 



An electron microscopy image of the olivine sample
shows a large empty dome structure where magnesium under high-pressure water precipitated as magnesium oxide.
[Image: shim_graphic_2.png?itok=w1gUmImb]

 

These characteristics may also help solve the mystery of why Uranus’ atmosphere is much colder than Neptune’s, 
even though they are both water-rich planets. 
If much more magnesium exists in the Uranus’ water layer below the atmosphere, 
it could block heat from escaping from the interior to the atmosphere.

“This magnesium-rich water may act like a thermal blanket for the interior of the planet,” said Shim.

Beyond our solar system, these high-pressure and high-temperature experiments may also help scientists gain a greater understanding of sub-Neptune exoplanets, which are planets outside of our solar system with a smaller radius or a smaller mass than Neptune.

Sub-Neptune planets are the most common type of exoplanets that we know of so far,
and scientists studying these planets hypothesize
that many of them may have a thick water-rich layer with a rocky interior.
This new study suggests that the deep oceans of these exoplanets
would be much different from Earth’s ocean and may be magnesium-rich.

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#35
Wouldn't Uranus be "different" because it's going around the Sun with poles in front and back, unlike Neptune where the poles are top and bottom ?

Like the a exo-planetary body running through the system to make this happen?

Bob...
"The Morning Light, No sensation to compare to this, suspended animation, state of bliss, I keep my eyes on the circling sky, tongue tied and twisted just and Earth Bound Martian I" Learning to Fly Pink Floyd [Video: https://vimeo.com/144891474]
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#36
...

good pdf

https://arxiv.org/pdf/1610.00548.pdf
Enceladus’s and Dione’s floating ice shells
supported by minimum stress isostasy

Enceladus’s gravity and shape have been explained in terms of a thick isostatic ice shell 
floating on a global ocean, 
in contradiction of the thin shell implied by librations. 
Here we propose a new isostatic model minimizing crustal deviatoric stress, 
and demonstrate that gravity and shape data predict a 38 ± 4 km-thick ocean 
beneath a 23 ± 4 km-thick shell agreeing with – but independent of – libration data. 

Isostatic and tidal stresses are comparable in magnitude. 
South polar crust is only 7±4 km thick,
facilitating the opening of water conduits and enhancing tidal dissipation through stress concentration. 
Enceladus’s resonant companion, 
Dione, 
is in a similar state of minimum stress isostasy. 
Its gravity and shape can be explained in terms of a 99 ± 23 km-thick
isostatic shell overlying a 65 ± 30 km-thick global ocean, 
thus providing the first clear evidence 
for a present-day ocean within Dione.

------


Methane in plume of Saturn's moon Enceladus could be sign of alien life, study suggests

https://www.nature.com/articles/s41550-021-01372-6
Bayesian analysis of Enceladus’s plume data to assess methanogenesis

Observations from NASA’s Cassini spacecraft
established that Saturn’s moon Enceladus has an internal liquid ocean.
Analysis of a plume of ocean material ejected into space
suggests that alkaline hydrothermal vents are present on Enceladus’s seafloor.

On Earth,
such deep-sea vents harbour microbial ecosystems rich in methanogenic archaea.

Here we use a Bayesian statistical approach to quantify the probability
that methanogenesis (biotic methane production)
might explain the escape rates of molecular hydrogen and methane
in Enceladus’s plume,
as measured by Cassini instruments.

We find that the observed escape rates
(1) cannot be explained solely by the abiotic alteration of the rocky core by serpentinization;
(2) are compatible with the hypothesis of habitable conditions for methanogens;
and
(3) score the highest likelihood under the hypothesis of methanogenesis,
assuming that the probability of life emerging is high enough.
If the probability of life emerging on Enceladus is low,
the Cassini measurements are consistent with habitable
yet uninhabited hydrothermal vents and point to unknown sources of methane
(for example, primordial methane) awaiting discovery by future missions.



The NASA Cassini mission revealed the existence of an ocean 
and hydrothermal activity underneath the Saturnian moon’s icy surface. 
Earth's hydrothermal systems team with microbial life. 
How likely are Enceladus’ hydrothermal vents habitable to Earth-like microorganisms?


Hydrothermal circulation is likely responsible
for what is perhaps the most notable feature of Enceladus:
a water-rich plume erupting from cracks in the ice at the South pole.

The Cassini spacecraft traversed the plume multiple times
and was able to perform mass-spectroscopy measurements of its composition.
The plume was found to contain a relatively high concentration of :
dihydrogen (H2),
methane (CH4),
and carbon dioxide (CO2).
In Earth’s hydrothermal vents,
methane can be produced abiotically in H2-rich fluids,
but at a slow rate.
Most of the production is due to microorganisms
that harness the chemical disequilibrium of hydrothermally produced H2
as a source of energy,
and produce methane (CH4) from carbon dioxide (CO2)
in a process called methanogenesis.

Searching for methanogens at Enceladus’ seafloor
would require extremely challenging deep-dive missions
that are not in sight for several decades.

We took a different, easier route:
we constructed mathematical models 
to quantify the likelihood that different candidate processes,
including biological methanogenesis,
might explain the Cassini data.


We looked at Enceladus’ plume composition
as the end result of several chemical and physical processes
taking place in the moon’s interior.
We first aimed at assessing what hydrothermal H2 production
would best fit Cassini’s observations,
and whether this production could provide enough ‘food’ Whip
to sustain a population of Earth-like hydrogenotrophic methanogens.

To do so, we developed a model for the population dynamics
of a hypothetical hydrogenotrophic methanogen Smoke 
whose thermal and energetic niche
was parameterized after known strains.

We were then able to assess whether a given set of chemical conditions
(e.g., H2 concentration in the hydrothermal fluid)
and temperature would provide a suitable environment for these microbes to grow,
and also what effect such a population would have on its environment
(e.g., on the H2 and CH4 escape rates in the plume).

So not only could we evaluate whether Cassini’s observations
are compatible with a habitable environment,
but we could also make quantitative predictions about observations
to be expected should methanogenesis actually occur at Enceladus’ seafloor.

We found that the amount of dihydrogen escaping in the plume
is compatible with deep-ocean conditions
allowing the growth of the modeled hydrogenotrophic methanogen. Dance2

Interestingly, if such microorganisms were actually consuming this dihydrogen,
the change in the plume’s hydrogen content would likely be negligible.
Thus, the detection of dihydrogen in the plume
may not be interpreted against biological methanogenesis
in Enceladus’ putative hydrothermal environment
(or in analogous terrestrial hydrothermal vents).
Furthermore, even the highest possible estimate of abiotic methane production (without biological aid)
from known hydrothermal chemistry is far from sufficient
to explain the methane concentration measured in the plume.
In contrast,
biological methanogenesis could produce enough methane to match Cassini’s observations.

We developed our model to test, 
or even reject the hypothesis of biological methanogenesis using the Cassini data. 
What we found is that our current understanding of Enceladus’ interior, 
of hydrothermal chemistry, 
and of methanogenesis does not allow to reject this hypothesis ;
in contrast,
the hypothesis of only abiotic Earth-like hydrothermal activity
to explain the Cassini data is rejected. Whip

So, what does this work actually teach us? First, it gives us some guidance on research warranted for a better understanding of the observations made by Cassini. We need to elucidate the abiotic processes that could produce enough methane to explain the data. For example, methane could come from the pyrolysis of primordial organic matter putatively present in Enceladus’ core, which could be partially turned into dihydrogen, methane and carbon dioxide through the hydrothermal process. We are not able yet to quantify methane production by this process, but improving our understanding of Enceladus’ history would be helpful.

In particular,
if Enceladus formed through the accretion of organic-rich material
(e.g.  cometary),
the hypothesis of the plume methane coming from pyrolysis may be very plausible.
An alternate mechanism is the outgassing of primordial methane
buried in Enceladus since its formation.
Having such mechanisms in mind,
we asked:
how would our results change
if arbitrarily large quantities of methane could be produced
by an abiotic mechanism in Enceladus’ interior?

We found that the combination of an elevated abiotic methane production,

together Herethere 
with biological methanogenesis  Gangup
could yield the observed abundance of methane in the plume.  {no shit Sherlock} Pennywise 

In this thought  Doh experiment, rejecting either hypothesis
(abiotic methane production vs. biological methanogenesis)
partly boils down to how probable
we believe these hypotheses are a priori.
For example, if we assign a low probability for life emergence in Enceladus,
the hypothesis of pyrolysis turns out to be strongly supported.


DIRECT LINK TO FULL PDF ARTICLE


https://www.nature.com/articles/s41550-0....space.com

give it time to load up the full text with images

...
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#37
...and now they're claiming that one of the rovers  (Opportunity, I think)
coincidentally  Dance2 landed at the chief location of methane release.

Of course the finding, and what it means, will depend upon the Vatican
issuing the ultimate "nihil obstat" as per a biologic connection... Alien2
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#38
The latest study has revealed that theres no God, so we can dissolve Vatican.

Here it is ..  Doh

Driver crashes after letting 'God take the wheel'

Woman Crashes Car At 190km/h After Telling God 'To Take The Wheel' (ladbible.com)

A woman in Ohio ended up crashing her car at 190km/h after relying on divine intervention to steer the vehicle.
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