General principles of international environmental and space law applicable to the protection of dark and quiet skies

Abstract The ambitious deployment of swarms of spacecraft into Low Earth Orbit (LEO) has resulted in the rapid and increasing degradation of the night sky visibility. While commercial rationales exist for this rapid rise of large satellite constellations (so-called “megaconstellations”) their negative effects on astronomy, and other uses of the night sky, have implications on the future sustainable and equitable uses of outer space. The special regimes of international space law, as found in the 1967 Outer Space Treaty and subsequent United Nations treaties on space, as well as in national regulation, have not provided the requisite guidance. Likewise, the regime of international environmental law, arguably more robust, fails to provide necessary guidance on the protection of the night sky from anthropogenic space objects. This article surveys the regimes of space law and environmental law for commonalities and points of convergence in an effort to strengthen the protection of the night sky and to offer pathways forward for concerned stakeholders.