Chile’s 1980 Constitution stands out globally for instituting strong private property rights over many things—including water, mineral concessions, education, and health services—with the result that access to basic human needs is at the mercy of the market, often leading to higher costs for low-income people and increasing inequality. A major objective of the CC was to address or reverse these dynamics by introducing novel notions of property such as common goods—as distinct from public goods—and using the concept of ‘natural commons’ within environmental governance. This chapter explores the natural commons through a novel lens—the movement to protect dark night skies—and acknowledges long histories in Chile of astronomy research conducted by Indigenous peoples, community organizations, and university scientists. Studying two constitutional articles in particular, this chapter examines the possibilities they open up for reimagining nature, knowledge, research relations, and the critical framing of environmental justice issues.