Thu. May 26th, 2022

I’m outside on my rural Saskatchewan farm chatting with my neighbors, whom I have invited over to enjoy the night sky through my telescope.

After shouts and open-mouthed amazement at Saturn’s rings and lights that have traveled through space for more than two million years to reach our eyes from the Andromeda Galaxy, our conversation inevitably turns to the pandemic, our work from home, and complaints about the Internet in the countryside. My neighbor accidentally mentions that they have just switched to using Starlink as their ISP.

I look up and notice a bright satellite moving across the sky, almost certainly a Starlink, as they now make up almost half of the nearly 4,000 operational satellites, and they are extremely bright. I take a deep breath and carefully consider how to discuss the significant costs that we all have to pay for Starlink internet.

I do not blame my neighbors for switching. Here, as in many rural parts of North America, there are no good internet opportunities, and with many people working and taking lessons from home during the pandemic, everything that makes life easier is accepted immediately.

But I know exactly how high these costs can be. My paper comes in The Astronomical Journal, have predictions of what the night sky will look like if satellite companies follow their current plans.

I also know that because of the geometry of the sunlight and the orbits chosen, 50 degrees north of where I live will be the hardest hit part of the world.

Without any regulation, I know that in the near future, one out of every 15 points you can see in the sky will actually be relentlessly crawling satellites, not stars. This will be devastating to research in astronomy and will completely change the night sky worldwide.

The future is too bright

To find out how hard the night sky will be affected by sunlight reflected from planned satellite mega constellations, we built an open source computer model to predict satellite brightness seen from different places on Earth, at different times of the night, in different seasons.

We also built a simple web app based on this simulation.

Our model uses 65,000 satellites in the orbits submitted by four mega-constellation companies: SpaceX Starlink and Amazon Kuiper (USA), OneWeb (UK) and StarNet / GW (China). We calibrated our simulation to match telescopic measurements of Starlink satellites, as they are by far the most numerous.

Starlink has so far made some progress towards attenuating their satellites since their first launch, but most are still visible to the naked eye.

Our simulations show that from anywhere in the world, in every season, there will be dozens to hundreds of satellites visible for at least an hour before sunrise and after sunset.

Right now, it’s relatively easy to escape light pollution from cities to dark skies while camping or visiting your cabin, but our simulations show that you can not escape this new satellite light pollution anywhere on Earth, even at the North Pole.

The hardest hit places on Earth will be 50 degrees north and south, near cities like London, Amsterdam, Berlin, Prague, Kiev, Vancouver, Calgary and my own home. On summer solstices, from these latitudes, close to 200 satellites will be visible to the naked eye all night long.

I study the orbital dynamics of the Kuiper Belt, a belt of small bodies beyond Neptune. My research relies on long-term exposure, wide-field imaging to detect and track these small bodies to learn about the history of our solar system.

The telescopic observations that are the key to learning about our universe are becoming much, much more difficult due to unregulated evolution of space.

Astronomers make some mitigation strategies, but they will require time and effort, which should be paid for by mega-constellation companies.

Unknown environmental costs

Starlink Internet may seem cheaper than other rural options, but this is because many costs are relieved. An immediate cost is atmospheric pollution from the hundreds of rocket launches required to build and maintain this system.

Each satellite deployment dumps used rocket bodies and other debris into an already crowded low orbit around the Earth, increasing the risk of collisions. Some of this space debris will eventually fall back to Earth, and the parts of the globe with the highest satellite density above will also be the most likely to be literally affected.

Starlink plans to replace each of the 42,000 satellites after five years of operation, which will require the de-orbit of an average of 25 satellites a day, about six tons of material. The mass of these satellites will not disappear – it will be deposited in the upper atmosphere.

Because satellites are mostly composed of aluminum alloys, they can form alumina particles as they evaporate into the upper atmosphere, potentially destroying ozone and causing global temperature changes.

This has not yet been studied in depth because low orbit around the Earth is not currently subject to any environmental regulations.

Regulation of the sky

Currently, low orbit around the Earth, where all these satellites are scheduled to operate, is almost completely unregulated. There are no rules on light pollution, atmospheric pollution from launches, atmospheric pollution from re-entry or collisions between satellites.

These mega-constellations may not even be economically viable in the long run, and internet speeds may be lowered to a requirement when many users connect at the same time or when it is raining.

But companies are launching satellites right now at a hectic pace, and the damage they are doing to the night sky, the atmosphere and the safety of low orbit around the Earth will not be regretted even if the operators go bankrupt.

There is no doubt that internet users in rural and remote internet have in many places been left behind by the development of internet infrastructure. But there are many other options for internet delivery that will not result in such extreme costs.

We cannot accept the global loss of access to the night sky that we have been able to see and connect with as long as we have been human.

With collaboration instead of competition between satellite companies, we could have many fewer in orbit. By changing the design of the satellites, they could be made much weaker and have less influence on the night sky. We do not have to choose between astronomy and the Internet.

But without rules demanding these changes, or strong pressure from consumers indicating the importance of the night sky, our view of the stars will soon be changed forever. The conversation

Samantha Lawler, Assistant Professor of Astronomy, University of Regina.

This article is republished from The Conversation under a Creative Commons license. Read the original article.


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