Potential and perils: paths to protecting lunar sites of extraordinary scientific importance (SESIs) for astronomy before it is too late.

The Moon presents unique opportunities for high-impact astronomy that could enhance our understanding of our solar system, the possibility of life beyond Earth, and the evolution of the universe. A handful of locations on the lunar surface are 'sites of extraordinary scientific importance' (SESIs) for such studies, presenting opportunities for astronomical research unmatched anywhere else. For instance, the farside of the Moon, the most radio-quiet location in the inner solar system, could allow for the emplacement of telescopes to study the cosmic Dark Ages in ways that are impossible elsewhere. However, we are also on the cusp of a broader lunar renaissance. A flurry of upcoming missions, both scientific and non-scientific, will target some of these very same sites and threatens to degrade their value to science. Protecting these sites is an urgent matter. Two major international efforts to create rules for activities on the Moon are afoot, but so far neither emphasizes protecting SESIs. To safeguard the exceptional scientific opportunities on the Moon, astronomers should engage these international rulemaking efforts and steer them towards ensuring the preservation of SESIs for research and discovery. We propose elements of a programme of action to adopt during a crucial, but closing, window. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades (part 2)'.

Concentrated lunar resources: imminent implications for governance and justice.

Numerous missions planned for the next decade are likely to target a handful of small sites of interest on the Moon's surface, creating risks of crowding and interference at these locations. The Moon presents finite and scarce areas with rare topography or concentrations of resources of special value. Locations of interest to science, notably for astronomy, include the Peaks of Eternal Light, the coldest of the cold traps and smooth areas on the far side. Regions richest in physical resources could also be uniquely suited to settlement and commerce. Such sites of interest are both few and small. Typically, there are fewer than ten key sites of each type, each site spanning a few kilometres across. We survey the implications for different kinds of mission and find that the diverse actors pursuing incompatible ends at these sites could soon crowd and interfere with each other, leaving almost all actors worse off. Without proactive measures to prevent these outcomes, lunar actors are likely to experience significant losses of opportunity. We highlight the legal, policy and ethical ramifications. Insights from research on comparable sites on Earth present a path toward managing lunar crowding and interference grounded in ethical and practical near-term considerations. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades'.