Blinded by the Light

29 May 2019

Sixty Starlink satellites ready for launch. SpaceX
Sixty Starlink satellites ready for launch.

We live in an information age. Our ability to connect with others and exchange information is a vital part of modern life. Unfortunately, our current network of Internet and mobile phone towers is not particularly equitable. Urban areas tend to have access to broadband connectivity, while rural and poor areas tend to be limited to slow speed connections if at all. This cascades into a disparity of opportunity that continues to widen the technological divide. So imagine if we could create a network accessible to almost everyone equally.

This is the idea behind the Starlink project. A satellite-based Internet that could give you access to the world no matter where you are. With continuous coverage over populated areas, it could truly be a global communication system.

But there are challenges. To provide global coverage, Starlink will need to maintain about 12,000 satellites in low Earth orbit. That’s more than the number of satellites launched since Sputnik 1 in 1957. There are currently about 5,000 satellites in Earth orbit, of which only about 1,900 are operational. To minimize space debris, the satellites would be designed to burn up in Earth’s atmosphere naturally after a few years.

But even with such precautions, there is reason for concern. With a complete Starlink network there would always be several of these satellites within your line of sight. You would always be able to see a few drifting overhead, particularly in early morning and late evening. Observations of the first Starlink launch saw the satellites shining at magnitude 3 or even 2, which is particularly bright for a satellite. Starlink will change our view of the night sky.

The impact on visible light astronomy will likely be small. The satellites will drift by quickly, and those types of transient signals are relatively easy to filter out. But radio astronomy is a different story. Unlike many satellites, the Starlink satellites will be broadcasting strong radio signals all the time. In visible light, it would be like a beacon light they use on police helicopters. Imagine trying to observe the night sky with a few of them drifting overhead all time. Starlink will be the brightest 12,000 objects in the radio sky, and they could effectively end radio astronomy at it’s operating frequencies. This doesn’t mean radio astronomy is over, but it does mean it will have to adapt.

When Galileo first raised a telescope to night sky, light pollution was almost non-existent. With the invention of electric lighting centuries later, humanity was able to fill the night with light. It made our world safer and more vibrant, but it also led to the gradual fading of the night sky from our everyday lives. Starlink is another step on that path. Giving us more connections while changing our view of the night.

There will be real benefits to satellite Internet. Greater connectivity is a good thing. But we should also recognize what we stand to lose. It’s important to recognize both and strive for a balance between them, lest we are simply blinded by the light of our desires.