Abstract EANA2025-79

Intro: There has been a global surge in lunar missions, most intended to explore the surface and sub-surface environments where water-ice might be present. Although exploration for water-ice is mainly driven by resource utilisation, its scientific potential and that of associated deposits (organic and inorganic) in or near the permanently shadowed regions (PSRs) of the Moon cannot be overstated (e.g. [1,2]).  In this context, the potential organic contamination of the PSRs through landed missions in their vicinity or surface exploration activities elsewhere on the Moon must be assessed. At the request of the European Space Agency (ESA), the European Science Foundation (ESF) assembled a working group to review the current planetary protection (PP) protocols for the Moon, specifically in the context of organic and biological contamination of the lunar PSRs by future exploration activities. The current COSPAR PP Policy for the Moon is guided by its unique traits as a celestial body devoid of indigenous life but harbouring regions of substantial astrobiological interest, such as the PSRs [1,2]. Currently, the Moon falls into Category II, which is subdivided further for lunar surface missions. Category IIa includes lander missions, excluding areas defined in Category IIb and requires PP documentation and an organic inventory - limited to organic products released into the lunar environment by the propulsion system. Category IIb includes lander missions that access PSRs and/or the lunar poles, requiring additional documentation to IIa of an inventory of organics on the spacecraft with a mass exceeding 1 kg [3]. Contamination types and sources: Three main lunar environments are identified, which are susceptible to organic contamination: exospheric, surface and subsurface. The extent and duration over which potential contaminations (exhaust products, outgassing materials, life-support systems, human waste, etc) remain at the surface or in the exosphere are currently unknown. Should drilling, or trenching, etc. be involved, then a significant unknown in this context is the downward diffusion of contamination. Based on current evidence, it is also difficult to evaluate biological contamination of the lunar PSRs. Assessing and quantifying lunar organic contamination inventory: The declared materials lists and inventories are provided by spacecraft operators from which the amount of organics carried by space missions can be estimated. However, it is not yet possible to assess the impact of such contamination on compromising the scientific potential of PSRs for addressing topics such as prebiotic chemistry. Preliminary recommendations: While acknowledging the proprietary needs of industry, we recommend increased dialogue between the science community and industry to identify mutually agreed pathways for lunar exploration, which minimises, if not eliminates specific contamination. Laboratory experiments and numerical simulations should be performed to better understand the distribution and longevity of organic contaminants introduced to the lunar environment by each mission [3] and the potential of contaminants to reach subsurface deposits and perform ground-truthing with real data, if available. These models should be routinely updated considering new data. Rules and international agreements for environmental protection of Antarctica could be considered as an example for Moon protection, especially in PSRs. A continuing open dialogue among stakeholders is necessary to develop a common understanding and agreement for the sustainable exploration of the Moon, which could then become a blueprint for exploring other targets in the Solar System.

References: [1] Crawford, I.A., Prem, P., Pieters, C. and Anand, M. (2022) Managing activities at the lunar poles for science. Space Research Today (215), pp. 45-51. [2] The Scientific Context for Exploration of the Moon, US National Academies Press (2007); https://nap.nationalacademies.org/read/11954/chapter/1. [3] COSPAR Policy on Planetary Protection, Space Research Today, 211, 12-25 (2021) [4] Paiva, F. S. & Sinibaldi, S. (2025). Can spacecraft–borne contamination compromise our understanding of lunar ice chemistry? Submitted to JGR: Planets