New Doubts About NASA’s ‘Potential Mars Biosignatures’

Jezero crater on planet Mars, Martian panorama with dry river mattress

getty

NASA’s information that its Perseverance Rover discovered potential biosignatures in rocks at Mars’ Jezero Crater is considerably down for the depend because the findings at the moment are being challenged by main geoastronomer Stephen Mojzsis. Mojzsis could also be greatest recognized for throwing chilly water on NASA’s 1996 announcement detailing putative proof that the “Allan Hills” Mars meteorite contained proof of historic microfossils.

Mojzsis, presently on the University of Bayreuth’s Bavarian Geoinstitute in Germany, is now disputing the Perseverance Rover’s “potential biosignature” speculation which was printed solely a few weeks in the past within the journal Nature.

There is nothing about this chemistry that can not be defined by reactions that may occur within the absence of life, Mojzsis advised me through electronic mail. The documented natural matter, phosphate minerals and proto-sulfide minerals are all present in meteorites, Mojzsis, who was not one of many Nature paper’s referees, advised me.

Mojzsis suspects that related non-biological chemical reactions may have occurred in these Martian rocks.

Although Mojzsis is at all times professionally cautious, his early response to the Allan Hills 84001 meteorite announcement (which was present in Antarctica in 1984) is now seen by the bigger planetary science neighborhood as prescient.

In truth, NASA’s assertions about microfossils in that Mars meteorite at the moment are considered with critical doubt; with most geologists noting that simply because the meteorite’s inside morphology could resemble bacterial microfossils, the extra possible clarification is that they have been attributable to non-biological processes whether or not in Antarctica or on Mars.

On The Sample Hunt

But that doesn’t imply we shouldn’t be heartened that Perseverance continues to be fulfilling its principal mission and on the market amassing samples in an space of Mars that does appear to be promising for locating historic signatures of life in no matter kind.

NASA’s most up-to-date announcement includes an space of Mars’ Jezero Crater that does appear to have been liveable some 3.5 billion years in the past. During its ongoing exploration and sampling of the realm, Perseverance collected a core pattern from the Bright Angel rock formation.

The formation is basically only a set of rocky outcrops on the sides of an historic river valley that NASA says is assumed to have been carved out by water speeding into the crater. During its time within the space, the rover collected a pattern known as “Sapphire Canyon.”

Now saved in a sealed tube contained in the rover, the “Sapphire Canyon” pattern is biding its time ready to be ferried again to Earth through what researchers hope might be a future follow-on pattern return mission.

Intriguing Minerals

We present that organic-carbon-bearing mudstones within the Bright Angel formation include submillimeter-scale nodules and millimeter-scale response fronts enriched in ferrous iron phosphate and sulfide minerals, possible Vivianite and Greigite, respectively, the Nature paper’s authors write.

Vivianite is often discovered on Earth in sediments, peat bogs, and round decaying natural matter, says NASA. And, equally, sure types of microbial life on Earth can produce Greigite, NASA notes.

The mixture of those minerals, which seem to have shaped by electron-transfer reactions between the sediment and natural matter, is a possible fingerprint for microbial life, which might use these reactions to supply power for progress, says NASA.

But are biosignatures one of the best clarification for these minerals at Jezero?

Vivianite is an fascinating phosphate mineral; not a type of issues which are touted as a “biomineral,” says Mojzsis. The 1890 Augustinovka meteorite that fell to Earth in Ukraine indicates that Vivianite can form in extraterrestrial or impact-related environments, he says. Greigite is also found in meteorites, including carbonaceous meteorites, says Mojzsis.

NASA argues that it seems unlikely that chemical byproducts of these ancient mudstones would be produced abiotically given the conditions known to be prevalent in Jezero Crater at the time these mudstones were formed.

There are ways to produce them without biological reactions, including sustained high temperatures, acidic conditions, and binding by organic compounds, says NASA. But the rocks at Bright Angel do not show evidence that they experienced high temperatures or acidic conditions, and it is unknown whether the organic compounds present would’ve been capable of catalyzing the reaction at low temperatures, NASA reports.

Yet Mojzsis again disagrees. Were microbes eating organic matter and breathing rust and sulfate in the iron and carbonaceous meteorites where similar minerals were also found? he asks. I think not, says Mojzsis.

What is NASA missing in its quest to find biosignatures on Mars?

We lack a firm idea of how life began on Earth, says Mojzsis. Any discussion of “biosignatures” rests on non-existent foundations if we do not have the slightest clue what the earliest most primitive life forms were actually like, he says.

The Nature paper’s lead author sees it differently.

The authors anticipate and welcome further discussion in the peer-reviewed scientific literature as a next step in the process of evaluating our findings, Perseverance mission scientist Joel Hurowitz and the Nature paper’s lead author at SUNY Stony Brook, told me via email.

The Bottom Line?

I have yet to see any compelling evidence whatsoever that life arose on Mars, says Mojzsis.

ForbesWhy Mars Could Hold The Keys To Understanding Life Here On EarthBy Bruce Dorminey