The Starlink Satellites

I have always considered satellites a part of observational astronomy. As an amateur astronomer, I enjoy simply looking up and trying to understand what I see in the heavens above. If a satellite happens by and I can watch its gentle arc for a while, I find that interesting and it enhances my enjoyment of being out under the stars.

Recently, SpaceX has been launching 100s of satellites into Earth orbit. The Starlink Satellite system will deliver high speed internet around the world. As a spectacle, I find the Starlink satellites fascinating to watch since they move in very large packs across the sky, not just single satellites but groups of them that move like a string of pearls across the sky for minutes at a time. I've observed these on many occasions over the past weeks. To see them, you will need a somewhat dark sky and a clear view especially toward the west. The website Heavens Above provides accurate information to help you locate times when the satellites will be visible based on your location on Earth.

Heavens Above - Starlink Passes

If you want to try to see the Starlink Satellites, your best bet is to find passes on Heavens Above when they will be appearing, which is typically within 1-2 hours after sunset based on your longitude and latitude. For city viewers, you will need to find passes that are at a brightness (magnitude) of 1 or 2. Higher numbers mean fainter satellites and they will be hard to spot. If you are in a darker location, you will be able to see passes down to magnitude 3 or even 4. Click on the image to the right to see an example, in this case based on my location in Munich, Germany.

The passes are quite impressive, with the graceful slow movement of a satellite from west to east being followed by a next satellite, and 15-20 seconds later another satellite, and so on. These chains of satellites are quite beautiful to see and if you are patient and look closely in the direction that Heavens Above advises, you will indeed find them. But you have to really pay attention to the cardinal direction (Azimuth, shown as east, west, north, south) and the height in the sky (Altitude, shown in degrees above the horizon).

There is controversy about these satellites. Because of the sheer quantity of them and the fact that they are bright enough to spot nearly every night, professional astronomers and astrophotographers are being disrupted in their work. SpaceX says they are working on ways to make the satellites less bright as they move up toward their final orbital altitude. The jury is out and we shall see how these satellites evolve over the coming months.

Postscript: on May 10th, 2020: SpaceX is working on plans to mitigate the impact of the Starlink satellites in the night sky, using a 'sunshade' approach.