A team of scientists involved in the search for extraterrestrial intelligence (SETI) has proposed a new approach to investigating the possibility of past alien civilizations by examining lunar soil for microscopic debris. Their study, currently under peer review for the International Journal of Astrobiology, suggests that remnants of advanced extraterrestrial societies could have been transported through space and might now be embedded on the Moon’s surface.

Led by Lewis Pinault, an affiliate scientist at the SETI Institute in Mountain View, California, and a researcher at Birkbeck College, University of London, the team explores how the gradual erosion of large-scale alien infrastructure—such as city-sized spacecraft, planetary mining operations, or extensive solar arrays—could release tiny particles into the cosmos. Over time, as alien civilizations decline or collapse, these materials could degrade further, dispersing clouds of microscopic debris across the galaxy.

The scientists modeled how such particles would traverse interstellar space and potentially enter the solar system, predicting that some might settle on the Moon, where erosion and geological activity are minimal compared to Earth. Pinault noted that if any technological civilization has existed within the galaxy, it is plausible that some of their material particles remain on the lunar surface.

The concept draws on observed examples within Earth’s orbit, where satellites shed trace amounts of material that float through space. By analogy, alien technologies might have similarly produced microscopic debris that drifted far from their origin.

Sofia Sheikh, also from the SETI Institute, described the research as a “creative and worthwhile avenue,” particularly given renewed global interest in lunar exploration. NASA’s Artemis program, which aims to return astronauts to the Moon in the coming years, could provide new opportunities to collect and analyze lunar samples that might contain evidence of such extraterrestrial particles.

The team’s work includes simulations of particle trajectories, showing how these microscopic fragments might survive space travel over millions of years and withstand impacts with the lunar surface. Detecting such debris could offer new insights into the existence of past technological civilizations beyond Earth, addressing one of humanity’s most profound questions: whether we are alone in the universe.

This novel strategy adds to the broader search for extraterrestrial intelligence by focusing on physical artifacts in our celestial neighborhood, rather than relying solely on signals or active communications from distant stars.