Israeli and American researchers say they have developed a new way to detect possible signs of life beyond Earth by focusing not on individual molecules, but on statistical patterns in how molecules are distributed within a sample. The approach could help future missions distinguish biological material from ordinary chemistry in samples from Mars, asteroids and icy moons.
For decades, scientists have searched for so-called biosignatures—chemical fingerprints that might indicate life. But existing methods often struggle with the realities of space exploration, where samples are degraded, incomplete or altered by radiation and geology. Organic molecules can form without life, and over time non-biological processes may blur or obscure any original signal.
“The key value of our approach is that it offers an easy way to identify organic material that is biological, as opposed to just organic gunk that formed in the early solar system,” said Professor Itay Halevy, who co-led the study at Rehovot’s Weizmann Institute of Science with Professor Yohai Kaspi.
The central idea of the work is that it shifts attention away from identifying specific compounds and instead examines the overall diversity of molecules in a sample. The researchers adapted statistical tools originally developed in ecology for measuring biodiversity, applying them to molecular mixtures as if they were ecosystems made up of different “species” of chemicals.
The study, led by researchers from Israel and the United States, analyzed more than 100 samples, including ancient Earth rocks, fossilized biological material such as dinosaur remains preserved in amber, and material returned from asteroids. Across these varied sources, the team looked for consistent statistical differences in how molecules were distributed. The findings were published in the journal Nature Astronomy.
“Many current methods of searching for extraterrestrial life are limited because they require either complicated processing of organic material or highly specific analytical methods, work you currently cannot perform in outer space,” lead researcher Dr. Gideon Yoffe explained.
The underlying chemistry depends on how molecules form. In non-living environments, simpler amino acids tend to dominate because they form more easily, while more complex molecules appear only rarely through chance reactions. Biological systems, by contrast, tend to produce a wider range of molecules because living organisms generate what they need to function, even if some compounds are chemically harder to make.
As Halevy noted, “Life will produce the building blocks it needs in order to function.”
This functional pressure creates a distinct pattern: Biological samples often show greater molecular diversity than non-biological ones, a signal that can be detected statistically rather than chemically.
Robust detection in harsh environments
Unlike many existing approaches, the method does not rely on pristine samples or detailed knowledge of a sample’s history. Instead, it can extract meaning even from material that has been altered by time, radiation or mixing processes. That makes it especially relevant for space missions, where ideal samples are unlikely.
The approach is being developed in connection with Eureka, a proposed Israeli mission concept targeting icy moons such as Europa and Enceladus, which orbit Jupiter and Saturn, respectively. Because subsurface oceans may exist beneath thick layers of ice, these environments are widely considered promising candidates in the search for life in the Solar System.
“These subterranean oceans are especially interesting because conditions there may permit the emergence of life,” said Kaspi.
The researchers say the technique could be implemented with relatively simple instruments, such as mass spectrometers that measure molecular abundances. Kaspi noted that the method does not depend on highly specialized laboratory systems. “Our approach does not require fancy analytical instruments,” he said. “It can be applied quite simply with any method capable of measuring relative abundances of different molecules.”
The team emphasizes that the method may remain useful even in harsh environments such as Jupiter’s radiation-battered moons, where energetic particles constantly modify surface chemistry. Despite this, they argue that the underlying statistical signature of life could still persist in protected or subsurface material.
If validated in future missions, the approach could be applied not only to icy moons, but also to meteorites and Martian rocks. In that case, evidence of life beyond Earth may emerge not as a dramatic encounter, but as a subtle statistical signal hidden within molecular data.
“I’ve been fascinated since childhood with anything connected to the search for life beyond Earth,” said Yoffe. “To me, this kind of detection would be one of the most exciting scientific discoveries ever made.”
