NASA Study Suggests Mars' Organic Molecules May Indicate Past Life
A NASA-led study finds that long-chain organic molecules detected on Mars are challenging to explain through non-biological processes alone, prompting further investigation into their origins.
In 2025, NASA's Curiosity rover detected long-chain organic molecules, specifically alkanes, in ancient Martian mudstones. A recent study led by Alexander Pavlov at NASA's Goddard Space Flight Center suggests that the original abundance of these molecules, prior to degradation by radiation over millions of years, is difficult to account for through non-biological processes alone.
The alkanes identified may be fragments of long-chain fatty acids, which on Earth are predominantly produced by biological activity. Initial samples from Curiosity showed alkane concentrations of approximately 30 to 50 parts per billion. Considering the Cumberland mudstone's exposure to Martian surface radiation for about 80 million years, researchers estimate that the original concentrations ranged from 120 to 7,700 parts per million.
The study evaluated various non-biological mechanisms, such as interplanetary dust, meteorites, atmospheric haze fallout, hydrothermal chemistry, and reactions like serpentinization, to explain the presence of these molecules. However, even when combined, these processes could not account for the inferred original abundance. The researchers stated, "We argue that such high concentrations of long-chain alkanes are inconsistent with a few known abiotic sources of organic molecules on ancient Mars."
While the findings do not confirm past life on Mars, they highlight the need for further investigation into the origins of these organic molecules. The study emphasizes that additional research is required to explore potential non-biological formation pathways and to understand how radiation affects organic molecules on Mars.