From Newsgroup: rec.aviation.military

from https://www.goodnewsnetwork.org/groundbreaking-nasa-discovery-is-closest-we-have-ever-come-to-finding-life-on-mars/

The so-called rCLLeopard spotrCY marks a mineral known on Earth for its production by microbes rCo Credit: NASA / JPL-Caltech / MSSS

Two minerals, known almost exclusively to be linked with microbial
metabolism, have been found in a recent drill sample by the Perseverance rover.

They sparked a flurry of excitement, and NASA Acting Administrator Sean
Duffy was quick to point out that gold-standard science will need to be performed on what he called rCLthe closest we have ever come to
discovering life on Mars.rCY

The hype comes entirely from the presence of two minerals: vivianite and greigite.

Per the Mineralogical Society of America, greigite is formed by
magnetotactic bacteria and sulfate-reducing bacteria in lake soils or hydrothermal vents. ItrCOs one of several materials scientists have
theorized could have acted as a catalyst for the origin of life, in part because a certain iron-based unit of greigite is present in a protein
needed to drive the acetyl-COA pathwayrCoa foundational metabolic process.

Vivianite is a hydrated iron phosphate mineral found in fossils, bivalve
and gastropod shells, and in human graveyards and coffins; the result of
a chemical reaction of the decomposing body with the iron enclosure. Sharp-eyed readers may think that the rCLvivirCY in vivianite comes from the word for life, but itrCOs actually named after a scientist called John
Henry Vivian.

Both vivianite and greigite were found in a recent core sample taken at Neretva Vallis, an ancient river channel about a quarter mile-wide that
once fed the lake at the bottom of Jezero Crater, the site where
Perseverance began its search for microbial life more than 5 years ago.

rCLThis finding by Perseverance is the closest we have ever come to discovering life on Mars. The identification of a potential biosignature
on the Red Planet is a groundbreaking discovery, and one that will
advance our understanding of Mars,rCY said acting NASA Administrator Sean Duffy.

rCLNASArCOs commitment to conducting Gold Standard Science will continue as
we pursue our goal of putting American boots on MarsrCO rocky soil.rCY


The reference to American boots isnrCOt just hyperbole. The recent NASA
budget was directly tied to a human mission to Mars, and it included the canceling of a potential billion-dollar sample return mission that would
have collected the Neretva Vallis cores, among dozens more, that
Perseverance has cached across the landscape.

Instead, NASA has decided that rather than investing so much on a never-before-attempted mission, it would be far more straight forward to
have astronauts collect them by hand.

Earth.com reports that the sample sediments showed a ring of vivianite penetrated by small rCLleopard spotrCY cores enriched in greigite, a pattern that matches a sequence seen in biologically mediated vivianite through
the influence of extracellular electron transfer, another fundamental metabolic pathway, that has been documented in biologically-live Earth sediments.

READ FURTHER: Fluorescent Rocks in Wind Cave National Park May Show How
Life Could Exist on One of JupiterrCOs Moons

None of this proves the Neretva Vallis samples were made by microbes,
but itrCOs certainly the closest scientists have ever come to detecting evidence of life.

The discovery, whether it proves to be life or not, does extend the
period during which Mars was potentially habitable (or not) to at least
as far forward in the planetrCOs history as when this river channel was
wet, an important reference date for future studies.

With such a strong biosignature being found within 6 years of
exploration, thererCOs every chance other such mineral cycling evidence
will be uncovered in future samples or missions, which in turn could be informed by the conclusions drawn from these core samples.

OTHER SPACE NEWS: Tiny Planet Makes Big Splash as Surprise Study Shows
it May Be Producing its Own Organic Compounds

The big question will be whether or not scientists can demonstrate that greigite and vivianite need biological life to form, or can they do so a-biotically. Alternatively, is there some signature that biotic
greigite and vivianite will always carry that a-biotic versions do not?

The answers to those questions will be the most impactful ones perhaps
ever made in the quest to discover whether Mars was habited by microbes
once upon a time.

SHARE This HUGE MILESTONE In The Story Of Discovering Life Beyond EarthrCa

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