A team of researchers has introduced a new method to detect extraterrestrial life by identifying statistical patterns across multiple planets rather than focusing on individual worlds. Led by Harrison B. Smith and Lana Sinapayen, the approach relies on life's potential to spread between planets and alter their environments. This 'agnostic biosignature' could help prioritize observations amid limited telescope time.
Researchers Harrison B. Smith from the Earth-Life Science Institute at the Institute of Science Tokyo and Lana Sinapayen from the National Institute for Basic Biology have proposed searching for alien life through shared patterns among exoplanets. Their study, published in The Astrophysical Journal, uses an agent-based simulation to model how life might spread via panspermia and terraform planetary environments, creating detectable statistical links between planetary locations and characteristics—even without clear biosignatures on any single planet. This method aims to minimize false positives from ambiguous atmospheric gases or uncertain technosignatures. By grouping planets by shared features and spatial positions, the team can identify clusters more likely shaped by biology, allowing scientists to focus follow-up observations efficiently. 'By focusing on how life spreads and interacts with environments, we can search for it without needing a perfect definition or a single definitive signal,' Smith said. Sinapayen added, 'Even if life elsewhere is fundamentally different from life on Earth, its large-scale effects, such as spreading and modifying planets, may still leave detectable traces.' The approach calls for better baselines on lifeless planetary diversity to distinguish biological patterns. Future exoplanet surveys could apply these statistical techniques to vast datasets.