A new study indicates that Amazon’s internet-beaming satellites in low Earth orbit are exceeding international brightness limits established to safeguard astronomical research. The research, which analyzed nearly 2,000 observations of the constellation, was posted to the preprint server ArXiv on January 12 and has not yet undergone peer review.
The study found that the Amazon LEO satellites recorded an average apparent magnitude of 6.28. While this magnitude typically renders them invisible to the naked eye, it is bright enough to affect scientific observations. The research concluded that 92% of these spacecraft surpassed the brightness limit recommended by the International Astronomical Union (IAU) for professional research interference.
Concerns have been raised regarding the impact on astronomical facilities globally. Anthony Mallama, lead author of the study and an astronomer at the IAU Center for Protection of the Dark and Quiet Sky, stated that challenges exist for both terrestrial and orbital observatories. Mallama specified that bright satellites are particularly problematic for large-scale astronomical surveys conducted at ground-based observatories, such as the Vera C. Rubin Observatory, and can also interfere with orbiting observatories like the Hubble Space Telescope.
In approximately 25% of observations, the Amazon satellites were bright enough to be visible without telescopes. This resulted in imaging data contamination with streaks and artifacts during twilight periods. The satellites currently orbit at an altitude of 391 miles (630 kilometers). Future spacecraft are expected to operate at lower altitudes of around 366 miles (590 kilometers), which could further increase their brightness.
Amazon initiated the launch of its constellation in 2025, with 180 satellites currently in orbit. Plans are in place to expand the constellation to over 3,200 spacecraft. Amazon LEO satellites are dimmer than AST SpaceMobile’s BlueBird arrays, but are slightly fainter than most of SpaceX’s Starlink satellites, which orbit at lower altitudes and spend more time in Earth’s shadow.
Experts acknowledge Amazon’s engagement with astronomers despite the brightness concerns. John Barentine, an astronomer at the Silverado Hills Observatory in Tucson, Arizona, noted that Amazon established a dialogue with astronomers early in the design phase of its constellation, indicating some success from this effort.
Since launching test satellites in 2023, Amazon engineers have implemented techniques to reduce reflected light. These include applying mirror-like coatings to the undersides of satellites and adjusting spacecraft orientation to minimize sunlit surfaces visible from Earth. A November 2025 report by Mallama and colleagues in the Monthly Notices of the Royal Astronomical Society determined that nearly all operational internet-beaming constellations, including China’s Qianfan and Guowang systems, exceed IAU-recommended brightness limits, with OneWeb satellites at higher altitudes being the sole exception.
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