![\"Lunar](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2026\/01\/Lunar-Spacecraft-Exhaust.jpg\")
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\n A rendering of a lunar lander of the European Space Agency\u2019s Argonaut program, which has its first mission to the moon scheduled for 2030. Methane released from spacecraft like these could contaminate icy regions of the moon\u2019s poles that might harbor clues about the origins of earthly life. Credit: \u00a9ESA <\/p>\n
Over half of the exhaust methane from lunar spacecraft could end up contaminating areas of
the moon that might otherwise yield clues about the origins of earthly life, according to
a recent study. The pollution could unfold rapidly regardless of a spacecraft\u2019s touchdown
site; even for a landing at the South Pole, methane molecules may \u201chop\u201d across the lunar
surface to the North Pole in under two lunar days.<\/p>\n
As interest in lunar exploration resurges among governments, private companies and NGOs,
the study authors wrote, it becomes crucial to understand how exploration may impact
research opportunities. This knowledge can help inform the creation of planetary
protection strategies for the lunar environment, as well as lunar missions designed to
minimize impact on that environment \u2014 and the clues about our past it may contain.<\/p>\n
The study appears in Journal of Geophysical Research: Planets, AGU\u2019s journal for original
research in planetary science.<\/p>\n
\u201cWe are trying to protect science and our investment in space,\u201d said Silvio Sinibaldi, the
planetary protection officer at the European Space Agency and senior author on the study.
The moon is a natural laboratory ripe for new discoveries, he said \u2014 but, paradoxically,
\u201cour activity can actually hinder scientific exploration.\u201d<\/p>\n
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Schematic representation of the physical processes and pathways modeled for exhaust At the moon\u2019s poles, craters cloaked in perpetual darkness (called permanently shadowed \u201cWe know we have organic molecules in the solar system \u2014 in asteroids, for example,\u201d Earth\u2019s dynamic, ever-changing surface likely erased any trace of what those original A molecular mad dash<\/strong><\/p>\n Sinibaldi and Francisca Paiva, a physicist at Instituto Superior T\u00e9cnico and lead author \u201cWe were trying to model thousands of molecules and how they move, how they collide with The model showed exhaust methane reaching the North Pole in under two lunar days. Within \u201cThe timeframe was the biggest surprise,\u201d Sinibaldi said. \u201cIn a week, you could have That\u2019s partly because the moon has almost no atmosphere of other molecules to bump into. \u201cTheir trajectories are basically ballistic,\u201d Paiva said. \u201cThey just hop around from one That doesn\u2019t mean there\u2019s nothing to be done to minimize contamination. Colder landing Above all, the duo said, the results need confirmation from both additional simulations Paiva hopes to study whether molecules other than methane, including those in spacecraft \u201cWe have laws regulating contamination of Earth environments like Antarctica and national Notes for journalists:\u202f\u202f This study is published in\u202fJournal of Geophysical Research:
CH4 molecules. Adapted from Prem et al. (2020).<\/strong> \u2014 Journal of Geophysical Research:
Planets<\/strong><\/p>\n
regions) hold ice which might contain materials delivered to the moon and Earth via comets
and asteroids billions of years ago. Scientists hope those materials might include
\u201cprebiotic organic molecules\u201d \u2014 key ingredients that, under the right conditions, may have
combined to form the original building blocks of life, such as DNA. Finding those
molecules in their original form could allow researchers to study how they gave rise to
life on Earth.<\/p>\n
Sinibaldi said. \u201cBut how they came to perform specific functions like they do in
biological matter is a gap we need to fill.\u201d<\/p>\n
molecules looked like long ago. The moon\u2019s surface, parts of which have remained
relatively unaltered for billions of years, may preserve a better record \u2014 especially in
the permanently shadowed regions, where molecules tend to accumulate due to cold
temperatures that slow their movement. Unfortunately, that may also include molecules
released by lunar spacecraft, potentially obscuring pristine evidence of life-originating
materials.<\/p>\n
of the study, built a computer model to simulate how that contamination might play out,
using the European Space Agency\u2019s Argonaut mission as a case study. The simulations
focused on how methane, the main organic compound released during combustion of Argonaut
propellants, might spread across the lunar surface during a landing at the moon\u2019s South
Pole. While previous studies had investigated how water molecules might move on the moon,
none had done so for organic molecules like methane. The new model also accounted for how
factors like solar wind and UV radiation would impact the methane\u2019s behavior.<\/p>\n
one another, and how they interact with the surface,\u201d said Paiva, who was a master\u2019s
student at KU Leuven and an intern at the European Space Agency during the research. \u201cIt
required a lot of computational power. We had to run each simulation for days or weeks.\u201d<\/p>\n
seven lunar days (almost 7 months on Earth), more than half of the total exhaust methane
had been \u201ccold trapped\u201d at the frigid poles \u2014 42% at the South Pole and 12% at the North.<\/p>\n
distribution of molecules from the South to the North Pole.\u201d<\/p>\n
Impeded only by gravity, methane molecules on the moon bound freely across the landscape
like bouncy balls across an empty room, energized by sunlight and slowed by cold.<\/p>\n
point to another.\u201d That\u2019s concerning, she explained, because it means there may be no
foolproof landing sites anywhere. \u201cWe showed that molecules can travel across the whole
moon. In the end, wherever you land, you will have contamination everywhere.\u201d<\/p>\n
sites, Paiva noted, might still corral exhaust molecules better than warmer ones. There
might also be ways around the contamination: Sinibaldi wants to study whether exhaust
molecules might simply settle on the icy surfaces of PSRs, leaving material underneath
unscathed for research.<\/p>\n
and real-life measurements on the moon. \u201cI want to bring this discussion to mission teams,
because, at the end of the day, it\u2019s not theoretical \u2014 it\u2019s a reality that we\u2019re going to
go there,\u201d Sinibaldi said. \u201cWe will miss an opportunity if we don\u2019t have instruments on
board to validate those models.\u201d<\/p>\n
hardware like paint and rubber, might also pose risks to research.<\/p>\n
parks,\u201d she said. \u201cI think the moon is an environment as valuable as those.\u201d<\/p>\n
Planets, an AGU journal.\u202fView and download a pdf of the study here. Neither this press
release nor the study is under embargo.\u202f\u202f<\/p>\n