2.2.3 MOC and the Moon

Since the Apollo missions of the 1960’s and 70’s, the Moon was considered to be sterile. However, since the early 2000s, permanently shadowed regions (PSRs) have been identified on the Moon (Figure 17) that are in permanent darkness and remain at temperatures cold enough for surface and subsurface water ice deposits. Estimated at about 1.8 billion years old, these areas could provide a record of how water was first delivered to the lunar surface and to the Earth-Moon system more generally, but they have the potential to act as a cold trap for pre-biotic organic molecules from early in the Solar System. Pre-biotic molecules are those that may have been the building blocks of the first life and should not be confused with probiotic molecules that you may have heard of promoted as an aid to gut health.

Figure 17 PSRs (indicated in blue) at the Moon’s south pole, identified by NASA’s Lunar Reconnaissance Orbiter spacecraft.

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A circular greyscale photograph covering approximately 600km diameter. The darker the grey the lower the altitude. The darkest features are round impact craters of different sizes. Several blue irregular blobs of different sizes are drawn overlain onto some impact craters.

Figure 17 PSRs (indicated in blue) at the Moon’s south pole, identified by NASA’s Lunar Reconnaissance Orbiter spacecraft.

PSRs have triggered further scientific interest in the Moon, but the water ice deposits have also been identified by government and commercial entities who wish to explore and utilise them as potential resources.

Since the Moon is in such close proximity to the Earth, robotic and human missions are easier and cheaper to accomplish than they might be for Mars, for example. The question therefore arises of whether the PSRs on the Moon need protection from MOC, (e.g., spacecraft propellant or organic materials the spacecraft are made of) and ultimately humans and any microbes they may carry. 

It also raises the question of whether certain PSRs should be scientifically protected (like national parks or UNESCO sites on Earth) so they can remain pristine, while other areas could be utilised for commercial gain.

How these two areas might interact together or how contamination may spread is still being debated, but it does mean that there is a requirement for clear guidelines on how both biological and organic contamination are dealt with when we leave Earth’s atmosphere.