Weizmann scientists propose a statistical test for spotting alien life

Researchers at Israel's Weizmann Institute of Science have proposed a new way to look for signs of life beyond Earth, published in June 2026 in the journal Nature Astronomy. The study was led by postdoctoral fellow Gideon Yoffe, working in the Earth and Planetary Sciences department with professors Yohai Kaspi and Itay Halevy, together with Fabian Klenner of the University of California, Riverside and Barak Sober of the Hebrew University of Jerusalem.

Instead of searching for one telltale molecule, the team looks at the overall pattern of a group of molecules such as amino acids, the building blocks of proteins. The idea borrows a tool ecologists use to measure biodiversity in a habitat. Non-living chemistry tends to produce mostly the simplest, cheapest amino acids, while living cells make a broader and more balanced mix, including complex molecules that are costly to build but useful. A sample's molecular diversity can therefore hint at whether biology was involved.

The researchers tested the approach on more than 100 samples, ranging from rocks about three billion years old and dinosaur eggshells to feathers preserved in amber and material returned from the asteroids Ryugu and Bennu. According to the Times of Israel, the method separated biological from non-biological material in every case. It is designed to work on samples that have been altered by heat, radiation or time, and the team reports that a similar pattern appears in fatty acids. Because it relies only on measuring relative amounts of molecules, it could run on relatively simple instruments such as mass spectrometers.

The team hopes the test will fly on Eureka, a proposed low-cost Israeli mission to Jupiter's icy moon Europa in the early 2030s that Weizmann scientists are planning with Israel Aerospace Industries. NASA scientist Chris McKay, who was not involved, told the Times of Israel the approach is likely to be less ambiguous than earlier experiments because it can detect the remains of life that is no longer active. The method could also be applied to meteorites and to rock samples returned from Mars.