Can these strange rocks be the first true proof of life on Mars?

The discoveries, published by the Grand International Team of Scientists, focused on the Crater Lake region known as the Bright Angel-IME formation selected from locations at the Grand Canyon National Park due to the lightweight color Martian Rocks. This area in the Neretva Vallis Mars channel contains fine-grained muds rich in oxidized iron (rust), phosphorus, sulfur and-hill-organic carbon. Although organic carbon was found on Mars, potentially from inanimate sources such as meteorites, this combination of material could be a rich source of energy for early microorganisms.

“When Rover entered Bright Angel and started measuring the compositions of local rocks, the team was immediately affected how different they were from what we saw before,” Tice, a geobiologist and astrobiologist at the Department of Geology and Geophysics. “They showed evidence of chemical cycling that organisms on Earth can use the production of energy. And when we looked even closer, we saw things that are easy to explain to the early Mars life, but it is very difficult to explain only to geological processes.”

Tice explained that “living beings are doing chemistry that mostly occurs in nature, given sufficient time and the right circumstances. In the best of our current knowledge, some of the chemistry that shaped these rocks required either high temperatures or life, and here we do not see evidence of high temperatures. However, these discoveries require experiments and fully exposed to the sample.

Tim published its discoveries in Nature.

A window in Mars aquatic past

The formation of light angels consists of sedimentary rocks delayed by water, including mud stones (fine -shed sedimentary rocks made of sludge and clay) and layered beds that suggest a dynamic environment of the flowing rivers and stagnant water. Using suits instruments, including Sherloc and Pixl spectrometers, scientists have discovered organic molecules and small mineral schedules that seem to have been formed through “order reactions”, chemical processes that include electron transmission. On Earth, these processes are often guided by biological activity.

Among the most striking features are tiny nodes and “reaction fronts” – the nickname “Maca seeds” and “leopard stains” Rover’s team – enriched with iron phosphate of iron (probably vivianit) and iron sulfide (probably Greigit). These minerals are usually formed in an environment rich in low temperatures, and are often associated with microbial metabolisms.

“They are not only minerals, but as they are arranged in these structures suggests that they have formed through regular iron and sulfur cycling,” Tice said. “On Earth things like these are sometimes formed in sediments where microbes eat organic substance and ‘breathing’ rust and sulfate. Their presence on Mars asks the question: Can similar processes appear there?”

Organic substance and regular chemistry

The Sherloc instrument has discovered Raman’s spectral feature known as G-OPSEG, signature of organic carbon, in several bright angelic rocks. The strongest signals came from a place called “Apollo Temple”, where both Vivianit and Greigite were the most represented.

“This co-location of organic matter and the regular sensitive minerals is very convincing,” Tice said. “This suggests that organic molecules may have played a role in launching chemical reactions that have formed these minerals.”

He does not note that it is important to understand that “organic” does not necessarily mean to form living beings.

“That just means having a lot of carbon-bonds,” he explained. “There are other processes that can make those other than life. The type of organic matter that have been discovered here could be produced by aviotic processes or could produce it to living beings. If they were produced by living beings, they should be degraded by chemical reactions, radiation or heat to create the G-OPSEG that we are now watching.”

The study describes two possible scenarios: one in which these reactions appeared with abiotic (guided geochemical processes), and the other in which the microbial life may have influenced reactions, as it does on Earth. Straighting, although some features of nodules and reaction fronts can be produced with amiotic reactions between organic substances and iron, well -known geochemical processes that could produce sulfur -related features usually act only at relatively high temperatures.

“All the ways we have the testing of these rocks on Rover suggest that they have never been heated in a way that could produce leopard stains and poppy seeds,” Tice said. “If this is the case, we need to seriously consider them the possibility that creatures like bacteria that live in Blato in Marsian Lake more than three billion years ago.”

Although the team emphasizes that the evidence is not the final proof of a past life, the findings are filled with NASA -I’s criteria for “potential biosignation” – features that guarantee further investigation to determine whether they are biological or abiotic origin.

A sample worth a return

The persistence has collected a pattern of the Bright Angel formation core, called “Sapphire Canyon”, which is now stored in the sealed tube carried by the Rover. This pattern is among those who are prioritized to return to Earth in a potential future mission.

“Returning this sample to Earth would allow us to analyze it to the instruments far more sensitive than anything we can send to Mars,” Tice said. “We will be able to look at the isotopic composition of organic matter, the mineralogy of fine proportions, and even the search for microphosils if they exist. We could also perform more tests to determine the most temperatures that have experienced these rocks and whether the geochemical processes of high temperatures will continue to be the best way to explain potential biosignation.

Tice, who has long studied the ancient microbial ecosystems on Earth, said that parallels between the Mars and the earthly process were striking – with one important difference.

“What is fascinating is that life may have used some of the same processes on Earth and Mars for about the same time,” he said. “We see evidence of microorganisms responding to iron and sulfur with organic matter in the same way in the rocks of the same age on Earth, but we would never be able to see the exact same features we see on Mars in the old rocks here. The processing of Tectonics plates warmed all our rocks to preserve them this way.