🌕 The day man will spread methane all over the lunar surface

Recent work indicates that gases emitted by spacecraft landers are likely to pollute the polar regions of our satellite, areas that could hold information about the origins of life on Earth.

Conducted by a Portuguese and European team, this analysis simulates the dispersion of methane from thrusters during lunar landing phases. Published in the Journal of Geophysical Research: Planets, it demonstrates that these organic molecules, on a world devoid of an atmosphere, move freely across the surface before eventually becoming fixed.


The models show that methane molecules even reach the opposite pole in less than two lunar days, or about two Earth months. Just over half of these pollutants then become trapped in craters plunged into permanent darkness.

These polar craters function as natural freezers, preserving water ice and other frozen compounds for billions of years. They could contain organic materials brought by comets or asteroids, thus constituting a unique window into the conditions that may have led to life on Earth. Unfortunately, their intense cold makes them sensitive to chemical inputs.

These findings raise questions for upcoming missions, especially those considering a permanent human presence. Space agencies and private actors will therefore need to integrate these risks into their plans, with the goal of limiting the chemical footprint on these sites of major scientific interest.

Protective measures, inspired for example by regulations in force in Antarctica, could be developed. The scientists behind the study hope this work will encourage more thoughtful landing approaches, possibly including dedicated instruments to confirm contaminant propagation models.

Organic molecules and the origins of life

These chemical compounds, built around carbon atoms, are frequently linked to biological processes. On the Moon, their presence could come from ancient impacts of comets or asteroids that transported these materials from outside the Solar System. These deposits, preserved in the polar ice, would offer a fossil record of primitive environments.

By analyzing these molecules, researchers aim to reconstruct the pathway that led to the emergence of terrestrial life. Geologically inactive, the Moon preserves these relics far better than our planet, where erosion and tectonics have erased them. It therefore represents an exceptional archive for tracing the chemical history of our planetary neighborhood.

The introduction of pollutants like methane, however, could obscure these ancient deposits. The search for prebiotic substances, fundamental for understanding the beginnings of life, would become more complicated. Preserving these zones thus appears as a priority for future work in astrobiology.

Robotic missions equipped with high-performance instruments could collect samples before any significant human arrival. Analyzing these materials in their original state might allow us to unravel the mechanisms that initiated life on Earth.