Shocking study published: These molecules from Mars are difficult to explain without the existence of life!

Rewind the clock by 80 million years

The Curiosity rover detected alkanes in concentrations of 30 to 50 parts per billion (ppb) in mud samples from Gale Crater, which is approximately 3.7 billion years old. Although significant, this discovery in itself was not conclusive proof.

However, Pavlov and his team asked two key questions: were there once more of these molecules and where could they have come from?

The rock sample, known as Cumberland, was exposed to relentless cosmic radiation on the surface of Mars for approximately 80 million years. This radiation gradually decomposes organic compounds.

Using a combination of laboratory experiments and mathematical models, scientists “turned back the clock” to estimate how much organic material was destroyed over that long period.

The results were astonishing. A new study published in the journal Astrobiology estimates that the rock originally contained between 120 and 7,700 parts per million (ppm) of long-chain alkanes or their precursors, fatty acids.

This is hundreds, even thousands of times more than what Curiosity directly measured.

The search for the source of the mysterious molecules

With such a high estimated concentration, the team started looking for possible non-biological (abiotic) sources. They analyzed all known mechanisms that could have brought or created organic molecules on ancient Mars.

This includes the deposition of interplanetary dust and meteorites, the formation of compounds in the atmosphere, and chemical reactions in hydrothermal sources, such as serpentinization.

However, their calculations showed that all these processes, even when added together, cannot explain such a huge amount of organic material. Delivery by meteorites and dust would be insufficient by several orders of magnitude, and the mineralogical composition of the rock does not indicate that it was exposed to the high temperatures necessary for hydrothermal synthesis.

“Our approach led us to estimate that the Cumberland mudstone conservatively contained 120 to 7,700 ppm long-chain alkanes and/or fatty acids before exposure to ionizing radiation,” the researchers write in their paper.

“We argue that such high concentrations are inconsistent with the few known abiotic sources of organic molecules on ancient Mars.”

Extraordinary claims require extraordinary evidence

Although the findings strongly point to a biological origin as the most likely explanation, scientists are extremely cautious. They do not claim to have found definitive proof of žlife. It is possible that there are non-biological processes on Mars for the creation of organic substances that we do not yet know, or that radiation acts on organic substances in a way that we do not yet fully understand.

Referring to Carl Sagan’s famous statement, the team points out that “extraordinary claims require extraordinary evidence” and notes that multiple independent lines of evidence will be needed to definitively confirm extraterrestrial life. Nevertheless, this research represents the strongest argument so far that the ancient Martian biosphere could have produced the organic material found in the rocks of the Gale crater.