[Reading Science] Astronomers Declare War on Musk

"Interference Occurs Due to Large-Scale Cluster Satellite Launch"
"Serious Disruption to Astronomy Research Including Space Observation"

"Astronomers, fight with your teeth and nails to protect the dark sky."

This is the appeal made by the astronomy research team at the University of Santiago de Compostela in Spain in a lengthy letter published on the 20th in the international academic journal Nature Astronomy, addressed to fellow astronomers. Recently, photos taken by the Hubble Space Telescope showed numerous satellites between stars, appearing like long scratches made by nails, making astronomical research nearly impossible.

Satellite interference phenomenon actually captured in an astronomical observation photo. Photo by the research team at Universidad de Santiago de Compostela, Spain

The research team called out the Starlink satellites launched by Elon Musk's SpaceX as the main culprits of this 'satellite interference' effect and urged for a fight. Due to worsening light pollution caused by increasing city lights and the multitude of satellites in low Earth orbit, they argued that immediate and strict regulatory measures, such as banning large-scale satellite constellations, are necessary as astronomical research has become unfeasible.

Astronomers have consistently raised concerns for over 60 years since the launch of humanity’s first artificial satellite in 1957, fearing interference with observations by ground-based telescopes, a primary tool in astronomy. Light-emitting diodes (LEDs), which can focus light on specific points to save energy and costs, were once considered an alternative, but have instead been found to worsen light pollution and have become a target of intense criticism. Originally known to have a lifespan of about 10 years, LEDs actually last 24 years?four times longer than the previously widely used sodium lamps?thereby exacerbating light pollution. Consequently, astronomers have built observatories in remote locations to avoid city lights, but now there are hardly any places left that meet the installation conditions.

Space telescopes installed in low Earth orbit face similar challenges. Recently, an amateur astronomy research team discovered that over 5% of the astronomical images taken by Hubble contained trails from Starlink satellites launched by SpaceX for space internet. Currently, more than 3,700 Starlink satellites have been launched and are operational, with plans to launch an additional 30,000. Other companies such as Amazon and OneWeb have also announced plans to launch hundreds of satellites each to build their own space internet networks.

Astronomers have raised issues as these satellites pose significant obstacles to the competitive observations made by expensive celestial telescopes. When SpaceX launched the first Starlink satellites in 2020, all astronomers voiced concerns that the bright light reflected from the satellites’ bodies and solar panels was visible to the naked eye. In recent years, observatories have experienced inconveniences such as closing shutters when satellites pass by or only observing briefly when the surrounding sky is clear.

Earlier this year, the U.S. National Science Foundation (NSF) and SpaceX agreed to reduce satellite interference, but astronomers’ dissatisfaction remains. They argue that expecting space development companies to achieve goals through self-regulation is na?vely optimistic.

The research team urged for stronger regulations and oversight, including stricter standards for large satellite constellations, limits on the number of orbiting satellites, and total artificial light regulations. In particular, they emphasized the need to strictly manage the total number of satellites by mandating the removal of malfunctioning satellites from orbit before launching replacements, and called for reviewing regulations that limit the operation of large satellite constellations. The team stated, "Now is the time to ban large satellite constellations and make significant efforts to reduce artificial nighttime lighting," adding, "The Earth definitely needs new policies for the night."