COSPAR Urges Global Action to Protect 'Dark and Quiet Skies' from Satellites

The rapid expansion of satellite constellations is threatening the fundamental ability of ground-based observatories to study the cosmos. At the 46th COSPAR Scientific Assembly, a panel of astronomers, policymakers, and space-industry executives convened to address the escalating conflict between global satellite services and scientific research.

Chaired by Marco Tavani, the session focused on the dual threats of light pollution and radio-frequency interference. According to reports from Science Magazine, the assembly highlighted how satellites disrupt optical astronomy by reflecting sunlight, which creates bright streaks that can saturate pixels or obscure transient objects, particularly during twilight. Simultaneously, radio astronomy faces threats from authorized signals, unintentional electromagnetic radiation from satellite electronics, and unwanted emissions that leak outside of allocated bands.

The Battle for the Night Sky

This tension arises from the deployment of massive satellite constellations, such as Starlink, which have significantly increased artificial light and radio noise in near-Earth space. To address this, the scientific community distinguishes between "dark skies," which require minimal artificial light for optical telescopes, and "quiet skies," which necessitate strictly controlled radio-frequency interference for radio observatories. As the orbital environment becomes more crowded, the ability to detect weak cosmic signals is increasingly compromised.

Implications for Discovery

Preserving these conditions is critical for high-precision research, including the detection of exoplanets and signals from the early universe. Beyond pure science, the panel noted that the preservation of the night sky is tied to ecological health, cultural heritage, and the long-term sustainability of the orbital environment. The consensus from the panel summary emphasized that while satellite technology provides vital services, its future depends on whether industry and governments can cooperate with scientists to ensure humanity does not lose its window to the universe.

Path Toward Policy

In response to these challenges, COSPAR announced plans to establish a dedicated Task Group. This group will work toward practical solutions, including the development of improved spacecraft designs and the implementation of coordinated observation strategies. On the diplomatic front, the UN Committee on the Peaceful Uses of Outer Space (COPUOS) has committed to keeping "Dark and Quiet Skies" as a dedicated agenda item for the next three years to foster international policy and coordination.