This paper examines the complex history of siting the Square Kilometre Array (SKA) telescope in South Africa and Western Australia, focusing on the intersection of astronomy, land use, and international collaboration. The SKA’s development has highlighted the political and ethical tensions surrounding "open skies" policies in radio astronomy, which advocate for global access to astronomical facilities, but often conflict with competing international interests, environmental impacts, and indigenous rights. In South Africa, while the project is often depicted as representing scientific progress on the African continent, it has raised concerns among rural communities over land appropriation and the political consequences of the SKA's presence. In Western Australia, similar issues emerged regarding the authority of indigenous communities and the negotiation of cultural heritage.

Additionally, this paper will explore why the United States, once a key player in the SKA, ultimately withdrew from the project. Factors such as funding challenges, shifting national priorities in radio astronomy, and disagreements over governance contributed to this decision, highlighting the broader political and financial pressures that shape large-scale scientific collaborations. Through this analysis, the paper offers insights into the global dynamics of contemporary astronomy, examining how the ambition for scientific collaboration is balanced by local and national political realities.

Exploring the frontiers of physics has often echoed the social and environmental issues associated with settler colonial frontiers. How can this be done otherwise? In this talk, I discuss how a particular neutrino experiment called TAMBO is trying to open up a new window to responsible physics. TAMBO is a planned observatory of cosmic neutrinos—invisible elementary particles released in highly energetic cosmic phenomena. The experiment is a leading-edge initiative to map the neutrino sky, pushing the frontier of what some have called neutrino astronomy. The experiment will take up several square kilometers and is aimed to be deployed in the Colca Valley of the Peruvian Andes—a region known for pre-Inca rooted inhabitants, condor habitats, and illegal mining activities. I report on the progress of this interdisciplinary collaboration as they try to find responsible and socially just ways of siting the experiment, and relate this story to recent histories of other particle physics frontiers.

Telescope siting has historically relied entirely upon ensuring sites meet the technical specifications required for observation. However, the astronomical community has obligations that extend beyond the technical, and the community is increasingly aware that as telescopes exist within a broader social context, the choice of site needs to be responsive to ethical, cultural, and environmental specifications just as much as technical ones. We need look no further than the ongoing conflict surrounding the Thirty-Meter Telescope on Mauna Kea or the Square Kilometre Array in South Africa, both of which have received widely publicized criticism, to see the importance of this lesson.

In recognition of these challenges, the Next Generation Event Horizon Telescope (ngEHT) collaboration has founded an interdisciplinary Responsible Siting working group that is integrated into the site selection process. We consider the societal impact of proposed telescopes by interfacing with local stakeholders in pursuit of a more equitable set of siting practices. These practices include the development of educational opportunities in local communities, engagement with indigenous land stewards and regional environmental groups, network building between community, academic, and governmental stakeholders, and transparent planning. This talk will present an overview of the ethical challenges of telescope siting, including the ethics of land use, the nature and importance of informed consent, and relationships between scientists and communities. It will then discuss the work being done by the Responsible Siting group with local groups at several sites in Jelm, Wyoming, the Canary Islands, and Tanzania.

In this presentation, we aim to explore, from the perspective of cultural astronomy, some of the main underlying colonial logics that inform the dynamics of academic astronomy in its interactions with local populations. We seek to provide an interdisciplinary analysis of these dynamics, while discussing and evaluating the potentials and limitations of various possible courses of action. To achieve this, we will employ a dual strategy. On one hand, we will focus on the analysis of a specific case: the dynamics surrounding the management of the dispersion of Campo del Cielo metallic meteorites in Argentina. In this context, we will draw upon 27 years of ethnographic fieldwork and archival research, as well as involvement in advising and monitoring processes of patrimonialization and Indigenous participation. On the other hand, we will place this case in a comparative perspective with other cases, leveraging ten years of experience coordinating the International Astronomical Union's Working Group "Astronomical Heritage in Danger," and active participation over the past four years in the Joint Committee on Culturally Sensitive Sites (CSS)—comprising representatives from the IAU, RAS, AAS, ISAAC, and SIAC. We will analyze these cases not as isolated incidents but by looking at the broader landscape and seeking to understand their structural characteristics. To this end, we will place them within their wider social context and critically examine some of the strategies recently deployed to address these tensions.