• stephentegler

A Rapidly Approaching Pandemic of Satellites

Updated: Jan 20, 2020

In 1994, an earthquake caused a city-wide power outage in Los Angles. During the night, 911 operators received numerous calls reporting a giant silvery cloud consuming the sky. The callers were seeing the Milky Way for the first time. Evidently, these city dwellers never saw a night sky free of light pollution. These callers were not unusual. Nearly 80% of Americans live in or close to the light pollution of cities and can’t see the Milky Way near their homes.

The Milky Way over Lake Mary taken with a Canon 6D camera showing the dark skies near Flagstaff, Arizona and the orange glow of light pollution from Phoenix over 100 miles away. Image Credit: Stephen Tegler

I’m in the 20% of Americans that can see the Milky Way near my house. For more than 60 years, my hometown of Flagstaff, Arizona has taken steps to protect its dark skies from light pollution. As a result, it’s an oasis for both stargazers and professional astronomers. Check out my image of the Milky Way taken minutes from my house. There aren't many places left in the United States dark enough to take an image like this one. But now there is a new and fast-moving threat to dark skies in Flagstaff and every other dark sky location on the Earth.

The global threat to our dark skies is coming from the commercialization of space. In the coming decade, SpaceX plans to launch 42,000 satellites as part of its Starlink network. Amazon wants to launch 3,000 satellites as part of its Kuiper Systems network. OneWeb wants to launch over 600 satellites with funding from companies like Coca Cola. That’s a total of almost 50,000 satellites. The goal of these satellites is to provide global 5G internet service.

Fifty-thousand new satellites is a huge number of satellites. For comparison, there are less than 2,000 active satellites in orbit now. There are only about 10,000 stars visible to the naked eye. So, Starlink, Kuiper Systems, and OneWeb plan to deploy more than twenty times the number of currently active satellites, and almost five times the number of stars visible to the naked eye. That’s a lot of satellites!

Reflected sunight from 25 Starlink satellites crossing in front of a cluster of galaxies. Image Credit: Victoria Girgis/Lowell Observatory

These satellites are bright. SpaceX launched its first batch of 60 satellites on a rocket in May of 2019. Astronomers at Lowell Observatory here in Flagstaff captured the dramatic impact of these satellites just after their launch on an image of a cluster of galaxies taken with a telescope. The bright steaks are the reflected sunlight off 25 of the 60 satellites as they moved through the field of view of the telescope.

To be fair, once the satellites reach their final orbital altitude, their density will be smaller than in the image, and they will be somewhat less bright. However, they will still be bright enough to see with the naked eye. You can see a dramatic simulation of the expected impact of only 12,000 satellites on casual stargazers in a "fast forward" video of the eastern horizon shown below and taken from Notice the satellite pollution is worst in the few hours after sunset (timestamp 0:10 to 0:50) and the few hours before sunrise (time stamp 4:30 to 5:08).

We're on edge of a new and unregulated frontier – the commercialization of space. It’s essential for companies like SpaceX to work with astronomers and policy makers around the globe to best utilize near Earth space for all of us. Otherwise, this pandemic of satellites could be a detrimental to casual stargazing, amateur astronomy, our most advanced astronomical observations, and even other down looking near Earth satellites. With the rise of commercialism and nationalism around the world, and especially in the United States, it appears the chances for international cooperation to solve yet another global environmental problem are bleak.

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