Amid widespread global concerns about water and air pollution, light pollution generally does not receive much attention. But light pollution has been exacerbated by the doubling of the amount of satellites and debris in low earth orbit since 2018. Such ‘mega-constellations’ have directly contributed to the brightening of the night sky, as highlighted by recent research. Operators such as SpaceX have been trying to reduce the brightness of their satellites through design modifications. However, despite these attempts to mitigate the issue, the substantial increase in the number of objects in orbit will continue to alter our night sky.
Satellites provide a wide range of critical services, including data transmission, internet connectivity, navigation support, and weather tracking, all of which are vital for our safety and security. Satellites are also increasingly important for the global economy, generating important revenue and jobs, and advancing technological progress in a variety of direct or indirect ways. They are now essential for international communication and Internet connectivity, particularly in remote and underserved regions. Satellites also gather data for various applications related to weather, climate, and environmental monitoring. This includes information on precipitation, sea surface temperatures, atmospheric temperature and humidity, sea ice extent, forest fires, volcanic eruptions, global vegetation analysis, and search and rescue operations. This data is utilized in diverse fields and applications, including in aiding farmers in the monitoring of crops, soil, and water, as well as in assisting governments in military operations, such as monitoring borders, military activities, and compliance with nuclear treaties.
At the same time, light pollution, both astronomical and ecological, can hinder astronomical observations and disrupt natural nocturnal ecosystems. Recently, there has been growing concern about the negative impacts of artificial light at night (ALAN) on humans and different species. Both flora and fauna depend on natural light and dark cycles to regulate essential activities, including reproduction, feeding, resting, and evading predators. For instance, many insects are drawn to light, and exposure to artificial sources can result in their demise. A decrease in insect populations can subsequently harm the many species that rely on them for food and pollination. Meanwhile, numerous national and international observatories have expressed growing concerns that brightness and light pollution from the drastic increase in satellites has already begun to hinder the efforts of scientists studying a range of phenomena, from colliding black holes to near-earth asteroids.
There are possible diplomatic, regulatory, and technical solutions to this problem. Collaborative efforts between regulatory bodies, policymakers, and the satellite industry could be established to ensure responsible satellite deployment. But while some of these discussions are already underway related to matters such as space debris, the secondary effects — such as light pollution — do not always receive sufficient attention. Implementing effective regulations and guidelines that consider the impact on astronomical observation and preserving the natural night sky is essential. Finally, steps such as optimizing satellite designs to minimize their interference with astronomical observations and promoting advanced technologies to reduce the brightness of satellites will also be necessary.
Katherine Salinas is Senior Program Coordinator for the Technology Policy program at ORF America.