Known non-living sources, from meteorites to surface chemistry, are insufficient to explain the organic compounds detected by NASA’s Curiosity rover, according to one researcher. new research Published in a magazine astrobiology.

In 2025, planetary scientists reported Long-chain alkanes have been detected at concentrations of approximately 30 to 50 ppb in the ancient Cumberland Mudstone in Gale Crater on Mars.

They proposed that the alkanes were derived from thermal decarboxylation of fatty acids during Curiosity’s analysis. Mars Sample Analysis (SAM) Instrument.

In a new study, Dr. Alexander Pavlov of NASA’s Goddard Space Flight Center and his colleagues argue that the measurements are just a lower bound, since most of the original organic material was likely destroyed by radiation over tens of millions of years.

The Cumberland Mudstone may have originally contained 120 to 7,700 ppm of long-chain alkanes or their fatty acid precursors prior to surface exposure.

“To reach this conclusion, we combined laboratory radiation experiments, mathematical modeling, and Curiosity data to ‘rewind the clock’ by about 80 million years, or the period during which rocks would have been exposed on the Martian surface,” the researchers said.

“This allowed us to estimate how much organic material was present before it was destroyed by long-term exposure to cosmic radiation, which is much higher than what typical non-biological processes can produce.”

The scientists also assessed whether known non-biological processes could explain the presumed unusually high abundances of long-chain alkanes.

Studies show that transport by meteorites and interplanetary dust particles is orders of magnitude inadequate, given the estimated deposition rates and the inability of dust particles to penetrate petrified rock.

Early Mars probably lacked the methane-rich conditions necessary to generate significant haze deposits, so it is unlikely that organic haze could form in the atmosphere.

The authors also investigated hydrothermal processes that can produce hydrocarbons under certain conditions.

Although laboratory experiments have shown that long-chain organic molecules can form hydrothermally, mineralogical analysis of the Cumberland mudstone shows that this mudstone has not experienced the high temperatures associated with such reactions.

This discovery suggests the more speculative possibility that some or all of the original organic material may have been produced by a hypothetical ancient Martian biosphere.

“We agree with Carl Sagan’s assertion that extraordinary claims require extraordinary evidence, and understand that the purported discovery of life on Mars will inevitably be subject to intense scrutiny,” the researchers said.

“Additionally, if we practice established norms in the field of astrobiology, we note that certainty of finding life beyond Earth requires multiple lines of evidence.”

“Nevertheless, our approach conservatively estimated that the Cumberland mudstone contained between 120 and 7,700 ppm long-chain alkanes and/or fatty acids before exposure to ionizing radiation.”

“We argue that such high concentrations of long-chain alkanes are inconsistent with several known sources of abiotic organic molecules on ancient Mars: transport of organic matter by interplanetary dust particles and meteorites, deposition by atmospheric fallout and photochemical haze, and production of organic matter by serpentinization and Fischer-Tropsch reactions on Mars.”

“In contrast, the ancient Martian biosphere was capable of enriching this level of complex organic matter in Martian mudstone deposits, and it is not unreasonable to hypothesize that transport of hydrothermally synthesized organics from other countries may have contributed to the alkane abundance found in the Cumberland Mudstone.”

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Alexander A. Pavlov others. Do the measured abundances suggest a biological origin of ancient alkanes preserved in Martian mudstones? astrobiologypublished online on February 4, 2026. doi: 10.1177/15311074261417879