Source: https://www.eso.org/public/announcements/ann22001/
7 February 2022
An international collaboration involving ESO has submitted a new paper to the United Nations Committee on Peaceful Uses of Outer Space (COPUOS) seeking better protections for the Earth’s dark and quiet skies. The paper was accepted for discussion today at the ongoing session of the COPUOS Scientific and Technical Subcommittee, marking the first time the dark and quiet skies have ever been tabled as a formal agenda item by the United Nations. The paper, which has been endorsed by Chile, Spain and Slovakia, encourages the international community to protect global astronomical observing capabilities from disruptive and harmful artificial interference.
The night sky offers a rich tapestry of stars to the fortunate viewer, but over the last few decades, its quality has been diminished as a result of encroaching ground-based light pollution. A new threat is now emerging: the large number of satellites being introduced into low Earth orbits. As many as 100 000 satellites could be placed into these orbits in the coming decade. While important for global communications networks, these satellites can disrupt astronomy because of the sheer number of them, their brightness in the sky, and their ubiquitous radio emissions. In particular, they can affect measurements which require twilight observation, such as searches for Earth-threatening asteroids.
By the 2030s more than 5000 satellites could potentially be detectable above a typical mid-latitude observatory at any given moment. This will be noticeable in all wide-field images obtained at twilight except those taken by the smallest optical telescopes. Large constellations of satellites also pose a challenge to radio astronomy. The sheer number of new satellites will result in thousands of additional radio transmitters, affecting the measurements made by highly sensitive radio telescopes. There is a clear need for better global coordination, policies and laws for dark skies protection, but also for radio-quiet skies.
Read more at https://www.eso.org/public/announcements/ann22001/