Mars Organics Are Hard to Explain Without Life, NASA-Led Study Finds
NEWS | 12 February 2026
In 2025, scientists reported the discovery of long-chain organic molecules called alkanes in the ancient mudstones of Mars. Now, in a new study, a team led by Alexander Pavlov of NASA's Goddard Space Flight Center argues that their inferred original abundance of these molecules, before millions of years of radiation destroyed much of them, is difficult to explain by non-biological processes alone. That does not mean that the detected alkanes are evidence of life on Mars; the conclusion relies on modeling how radiation breaks down organic material over time. However, the finding does suggest that the origin of these molecules warrants closer inspection. The interesting thing about the alkanes found in the Martian mudstone is that they could be fragments of long-chain fatty acids, which on Earth are produced largely – but not exclusively – by life. The initial Curiosity sample showed alkanes at concentrations of around 30 to 50 parts per billion, which isn't particularly high. Pavlov and his colleagues asked two questions: could there once have been more of them in the stone? And if so, where could they have come from? The Cumberland mudstone has been sitting on the surface of Mars, exposed to harsh radiation for about 80 million years, which would have slowly broken down any organic material in the rock. The researchers drew on laboratory radiolysis experiments to estimate how quickly radiation would break down alkane precursors, arriving at a much higher original concentration of 120 to 7,700 parts per million (ppm). Then, they considered the non-biological deposition and formation mechanisms that could have put them there – processes that include transport from interplanetary dust, meteorites, atmospheric haze fallout, hydrothermal chemistry, and reactions such as serpentinization. Even when combined, these processes were unable to approach the inferred original abundance of the molecules. "Our approach has led us to estimate that the Cumberland mudstone conservatively contained 120 to 7,700 ppm of long-chain alkanes and/or fatty acids before exposure to ionizing radiation," the researchers write in their published paper. "We argue that such high concentrations of long-chain alkanes are inconsistent with a few known abiotic sources of organic molecules on ancient Mars." Related: Life on Mars? NASA's Stunning Discovery Is The Best Evidence Yet The paper is very careful to point out that they are not claiming a definitive detection of life beyond Earth. There could be non-biological alkane formation pathways on Mars that we don't know about, or something we don't know about how radiation acts on organic molecules on Mars. Further research is required to fill in these blanks. It's been well established that Mars hosts many different kinds of organic molecules. The question now is what they are telling us about habitability – or lack thereof. The research has been published in Astrobiology.
Author: Michelle Starr.
Source