This story will be about the new Starlink satellites and the question: will they change our night sky in a way that ordinary people will notice?
Elon Musk plans to use many small satellites in a low orbit to bring internet broadband access to rural parts of the globe.
On May 23, 2019, a Falcon 9 rocket released 60 of the SpaceX Starlink satellites into low earth orbit.
However, soon after launch, there were reports the satellites were bright in the sky and they appeared as white lines in long-exposure pictures of the stars. The International Astronomical Union stated there may be unforseen consequences with the satellites, such as making it more difficult to study the universe and potentially affecting nocturnal wildlife. (Space.com)
SpaceX has permits to launch many more of the satellites, and deploying all of them would triple the amount of satellites in Earth Orbit. (New York Times)
The satellites have solar arrays which produce energy for the satellites but can bounce light at Earth. SpaceX claims the satellites will be less visible once they’re higher in orbit and are able to orient their solar arrays so they face the sun. Each satellite will fall back to Earth after about 5 years. (CNET)
But will these change our night sky in a way that ordinary people will notice?
They are most visible near dusk and dawn because in their orbit they can reflect sunlight after it’s already night on the ground. Once a satellite is in earth’s shadow, it doesn’t reflect light from the sun. Musk has stated that most people will not be able to notice them and that it’s possible to alter the solar panel configuration if needed so the satellites don’t appear in astronomical experiments. He’s also stated that he will make sure future satellites will be less reflective. (SpaceFlight Insider)
Jonathan McDowell, an astronomer who works for the Harvard Smithsonian Center for Astrophysics, said of rural areas, “You’ll still see them just at the limit of your vision — it will look like the whole sky is crawling.” (Washington Post)
Initial estimates found the satellites would be almost as bright as Polaris, the north star. Updated estimates find they will be much dimmer but there is the possibility they may be visible to the naked eye in areas with very low light pollution. The satellites also have the potential to “flare” by reflecting sunlight back at earth at certain angles. These flares could be as bright as Venus or Jupiter in the night sky. (National Geographic)