How to find life on other planets: a new method express
A chemical detective searches for life on other planets. Its tool is a mass spectrometer that identifies molecules by weight (the same device earthly forensic scientists use to analyze clues). Scientists equipped the detective to look for 56 telltale molecules: carbon chains of amino acids (protein building blocks), nucleobases (DNA letters), and fatty acids (the basis of fats).
The first test — Titan's haze. In its laboratory analog, phenylalanine (an amino acid key to proteins) and a multitude of fatty acids were found for the first time — a hint that complex chemistry is possible without life. In Martian gypsum from the Qaidam Desert, amino acids were neatly divided into biotic and abiotic, like fingerprints. Fatty acids, however, acted like double agents — they didn't reveal the secret.
So, the best guide is amino acids. They don't lie. Such a detective will fly to Mars to read the chemical chronicle of other worlds.
Original abstract
as written by the authors arXiv:2603.27598
Building blocks of life such as amino acids, nucleobases, and fatty acids are central to prebiotic chemistry and represent key targets in the search for planetary biosignatures. In planetary materials, biomolecules typically occur at trace levels within complex matrices, posing substantial analytical challenges, particularly for quantitative characterization. Here we develop a gas chromatography tandem mass spectrometry method that enables robust qualitative and quantitative analysis of 56 prebiotically relevant molecules. The method is applied to a Titan aerosol analog and, for the first time, to a Martian gypsum analog from the Qaidam Basin, revealing diverse inventories of amino acids, nucleobases, and fatty acids in both samples. In the Titan aerosol analog, the first detection of phenylalanine and an extensive inventory of fatty acids, together with elevated nucleobase abundances, offers new insights into atmospheric photochemical synthesis of prebiotic molecules. In the Martian analog sample, amino acids are detectable and exhibit pronounced biotic abiotic contrasts in abundance patterns relative to those observed in the Titan aerosol analog, whereas fatty acids show more overlapping abiotic and biotic signatures, highlighting the potential of amino acids as robust biosignatures. These results provide quantitative constraints on prebiotic chemical evolution and underscore the utility of GC-MS-MS for biosignature identification in planetary exploration.
Titan is the only place in the Solar System, besides Earth, with a dense atmosphere and surface liquid (methane lakes), and its aerosol haze resembles smog, from which organic molecules can arise.
In the novel 'Solaris', the planet's ocean creates complex structures on its own — much like Titan's atmosphere inadvertently 'sculpts' amino acids.