Existential Threat: ESO Warns of Satellite Plans from SpaceX and Others
The European Southern Observatory (ESO) has raised alarms regarding the potential placement of over 1.7 million satellites in Earth’s orbit. According to a recent study, these developments could have dire consequences for optical astronomy, labeling them an “existential threat.” Specifically, urban areas may only witness artificial points of light from these satellites, obscuring natural celestial phenomena. The ESO’s findings are being presented to the U.S. Communication Commission (FCC) amidst significant plans from companies like SpaceX and Reflect Orbital.
Growing Number of Satellites
The ESO highlights that the number of active satellites in Earth’s orbit has soared to over 14,000 since 2019. A staggering two-thirds of these belong to SpaceX’s Starlink internet constellation. Additionally, there are nearly 20,000 inactive satellites contributing to the growing problem of space debris. The imagery from time-lapse videos show countless light trails above ESO’s observatories in Chile. However, these trails pale in comparison to what we might see in the night sky should the current constellation plans gain approval and come to fruition.
Satellites Brighter than the Moon
Reflecting on their brightness, the ESO emphasizes that while SpaceX’s satellites contribute to light pollution, the plans proposed by Reflect Orbital are far more alarming. This startup intends to launch colossal mirrors into space designed to reflect sunlight onto the Earth’s surface, extending solar panel efficiency in generating electricity. Preliminary tests indicate that if one were to stand in the path of light from these mirrors—designed specifically for solar farms—it would appear four times brighter than a full moon. Critics argue that such a solution may not provide sufficient light for solar energy generation.
Even if not directly illuminated, each of these satellites would outshine Venus, known as the “Morning Star” in the sky. Reflect Orbital plans to expand its fleet to 50,000 satellites by 2035, which poses a severe risk for stargazers in urban settings. For instance, in a city like Munich, one might see hundreds of these satellites, making true star observation nearly impossible. While some satellites may not pose an immediate threat to casual stargazing, astronomers fear the ramifications will be catastrophic.
Impact on Astronomy
The Very Large Telescope (VLT) operated by ESO could experience a substantial reduction in usable observational time. Studies estimate that just two hours after sunset could result in a 28% decrease in the telescope’s field of view. Nature would be eclipsed, as human-made lights gradually dominate the night sky.
A Call for Regulation
To mitigate these repercussions, the ESO emphasizes the need to limit the total number of current and future satellites to 100,000. The lead author of the study, Olivier Hainaut, suggests that this cap is not absolute; ideally, a number closer to 50,000 would be preferred. However, this threshold is contingent upon each satellite’s brightness being under a magnitude of seven. Exceeding this brightness would necessitate reducing the overall number of satellites further.
The research paper detailing these findings is set to be published in Astronomy & Astrophysics and aims to engage with the FCC, which oversees most satellite approvals.
In conclusion, the satellite expansion plans from various companies pose a significant risk not just to optical astronomy, but to our relationship with the natural cosmos. As the ESO advocates for tighter regulations, the future of our night sky hangs in the balance.
