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A new study has provisionally found that Amazon Leo (formerly Project Kuiper), which is in the early stages of launching a new mega constellation of ultrafast broadband satellites into Low Earth Orbit (LEO) for the UK and globally, suffers from an all too familiar problem of being a bit too bright – potentially enough to disrupt observational sciences (astronomy).
The new service is currently in the commercial beta phase and will start to launch properly through 2026. The service currently has approval to deploy and operate their own initial constellation of 3,236 LEO satellites (altitudes of between 590km to 630km). A total of over 180 Kuiper satellites have already been placed into orbit (they need at least 500 for basic global coverage) and many more are due to follow over the next few years.
However, a new study from a group of astronomers affiliated with the International Astronomical Union (IAU) suggests that Amazon’s service, which is designed to compete with the likes of SpaceX’s Starlink constellation, also appears to suffer from the same brightness problem that we’ve seen occurring across various LEO satellite networks – some more than others.
Just to recap. The IAU recommends that LEO satellites should have a maximum brightness of magnitude +7 at altitudes of up to 550km. On this scale, the brightest objects actually have the smallest numbers (e.g. brilliant Venus can reach up to -4.6, while the North Star is dimmer at +2). If satellites are too bright then that can make it much harder to picture the night sky and do other things, such as to spot dangerous asteroids or detect key celestial events.
According to the new study, which used data collected from nearly 2,000 observations of Amazon’s new satellites, the brightness distribution of satellites at 630km was compared against the IAU’s recommended limits. “For satellites in their operational mode, 92.0% of observations exceed the research limit, while 24.7% exceed the aesthetic limit,” said the study.
The aesthetic limit reflects a Magnitude of 6 (i.e. objects that can be seen at locations where the sky is minimally affected by light pollution). You can see how the various constellations compare below.
Study Conclusion
The mean apparent magnitude of all Amazon Leo satellites is 6.28 based on 1,938 observations. For spacecraft in their operational mode, 92% exceeded the IAU brightness limit for interference with research, while 25% distract from aesthetic appreciation of the night sky.
The reflective characteristics are similar to Version 1 Starlink spacecraft. Both strongly scatter sunlight forward and backward. Based on private communication, Amazon is working on reducing satellite brightness.
The Amazon Leo constellation spacecraft are potentially impacting astronomical research and aesthetic appreciation of the night sky.
Brightness statistics for all major satellite constellations are kept up to date at our website, https://satmags.netlify.app/ .
At present this is less of a concern because Amazon has only launched 180 satellites, but it becomes more of a problem once thousands are up in the sky. For its part, Amazon Leo says they’re working with astronomers to help reduce the brightness problem, which has included “applying a custom dielectric film and non-reflective coating on all of our operational spacecraft,” said a spokesperson (credits to PC Mag). But by the sounds of it, this is already present on their existing satellites. Suffice to say, more changes may be required.