New study in “Nature Astronomy” featuring researchers from Freie Universität Berlin calls for novel approaches to astrobiology
№ 059/2026 from May 22, 2026
How likely is it that signs of extraterrestrial life are already out there, but we have simply not yet been able to detect them? An international research team has taken on this question in a study recently published in the scientific journal Nature Astronomy. The researchers analyzed the phenomenon of “false negatives,” cases in which evidence of biological activity in space is overlooked or incorrectly interpreted. Researchers from Freie Universität Berlin were involved in the study alongside other experts in the fields of planetary sciences and astrobiology.
The authors investigate the strategies currently used to search for extraterrestrial life, warning that they might have been too limited in scope. Space missions and tools have been designed to detect specific biosignatures that are already known. This means that – in contrast to the risk of detecting “false positives” – the risk of overlooking traces of life has rarely been taken into account in a systematic manner. The researchers advocate for a combination of new research strategies, laboratory experiments, models, fieldwork, and AI-based pattern recognition to make up for these shortcomings.
Why Do Traces of Life Sometimes Go Undetected?
“The search for extraterrestrial life is one of the major scientific questions of our time. However, we have to make sure that we do not orient our tools and methods too much toward what we already know,” says planetary scientist Dr. Nozair Khawaja from Freie Universität Berlin. “Otherwise we could end up missing forms of biological activity that are unusual or difficult to detect.”
The study “False Negatives in the Search for Extraterrestrial Life” proposes several reasons for potential misinterpretations of biosignatures. Chemical or geological processes may conceal indications of life, or traces of biological activity may be present but could remain undetected due to unsuitable measurement methods. “A simple way of illustrating this issue would be that if there were life under the surface of a celestial body, and you only looked at it from above, then these subterranean life forms could go unnoticed,” explains Professor Frank Postberg.
The researchers do not consider this issue to be a solely scientific problem. “A failure to identify signs of life could have grave political and economic consequences, for example, if the exploitation of raw materials on planets were to get the go-ahead without first verifying whether life forms exist there,” says Professor Lena Noack.
The study was led by Inge Loes ten Kate, professor of astrobiology at Utrecht University and the University of Amsterdam. Planetary scientists from Freie Universität Berlin also made significant contributions to the paper. Khawaja and Postberg explored whether potential traces of life remain hidden under the thick ice crusts on icy moons, as their subsurface oceans could be home to simple life forms. This research could be instrumental in developing concepts for future European Space Agency (ESA) missions to Enceladus, the sixth-largest moon of Saturn. Noack investigated abiotic baselines and models of scenarios for habitable planetary atmospheres. She also addressed the question of how typical biosignatures may change, be concealed, or otherwise be fundamentally different in other atmospheric environments, which could potentially result in false-negative results in the search for extraterrestrial life.
Freie Universität Berlin – a Driving Force in International Space Research
The participation of a number of researchers from Freie Universität Berlin in the study highlights the strong reputation enjoyed by planetary scientists in Berlin on the world stage. The German Research Foundation (DFG) recently approved funding for the new Collaborative Research Center (CRC) 1759 “Habitability as a Fundamental Planetary Process: Towards a Paradigm Shift Away from Our Perception of the Uniqueness of Earth” at Freie Universität Berlin. The group’s goal over the next four years will be to pursue interdisciplinary research on the planetary conditions that result in the emergence, evolution, and detectability of life beyond the Earth’s atmosphere.
As finding potential biosignatures or traces of habitability could also have far-reaching societal impacts, CRC 1759 will take a holistic approach and investigate ethical considerations in research and society regarding missions and the establishment of human outposts on other planets.
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