New Biosignature Method Could Transform Search for Alien Life

Scientists have long hunted for signs of life by searching for biosignatures — biological molecules such as amino acids and fatty acids. But detecting these compounds alone proves unreliable, since non-living chemical processes can produce them too. Now, a team led by Gideon Yoffe of Israel's Weizmann Institute has proposed a smarter approach: studying not just what molecules are present but how they are organized, a study published in Nature Astronomy.

Diversity as a Fingerprint of Life

In the study, following the ecological principles, the scientists studied approximately 100 samples from asteroids, meteorites, fossils, microbes, and soil. The study revealed that biological molecules have a unique organizational pattern. While amino acids created by biological means display a higher diversity and are better distributed, fatty acids demonstrate just the opposite—less diversity and unevenly spread. Moreover, the unique characteristics of biological molecules can be detected even in samples in bad shape. Indeed, dinosaur eggs found to possess specific patterns indicate the possibility of discovering ancient microbial signatures on Mars, where once the climate was much more favourable.

Europa Clipper: An Unexpected Ally

The method can be easily applied to the current mission carried out by NASA's Europa Clipper, which is on its way towards Jupiter's moon Europa and expected to reach it by 2031. Europa is thought to have an underground ocean with at least twice the volume of water that exists in the oceans on Earth, and hence, Europa is considered one of the best candidates for hosting life. Europa Clipper has an onboard surface dust analyserr that analyses ice particles collected from Europa's surface, along with the presence of amino acids.