Amazon's ambitious satellite internet project is facing a significant challenge: its satellites are too bright, potentially disrupting astronomical research. A recent study has revealed that the satellites in Amazon's low Earth orbit (LEO) constellation, designed to provide global internet coverage, exceed the brightness limits recommended by the International Astronomical Union (IAU).
The study, posted on the Arxiv repository, analyzed nearly 2,000 observations of Amazon's Leo satellites. It found that these satellites are causing issues for both ground-based and orbiting observatories. Lead author Anthony Mallama, an astronomer at the IAU Center for Protection of the Dark And Quiet Sky, explained that the brightness of these satellites is particularly problematic for large-scale surveys conducted at observatories like the Vera C. Rubin Observatory. However, they can also interfere with orbiting telescopes such as the Hubble Space Telescope.
This isn't the first time Mallama and his colleagues have studied satellite brightness. They've previously examined SpaceX's Starlink, the largest constellation in orbit with around 9,500 satellites, and AST SpaceMobile's BlueBird satellites, which are the brightest artificial objects in the night sky. Amazon's Leo satellites are significantly dimmer than BlueBirds and slightly fainter than most Starlink satellites, but they orbit at a higher altitude, around 366 miles (590 km).
Amazon has been proactive in addressing these concerns, engaging with astronomers and implementing measures to reduce the brightness of its satellites. One method is making the underside of the spacecraft mirror-like to reflect sunlight into space. Another is orienting the satellites' components so that observers on the ground don't see the sunlit sides. Despite these efforts, the study found that Amazon's Leo satellites are still causing issues.
The controversy surrounding this issue highlights the delicate balance between technological innovation and preserving the darkness of the night sky for astronomical research. As satellite constellations continue to expand, the need for collaboration between satellite operators and astronomers to find solutions that minimize interference is becoming increasingly crucial.
