Imagine the ground under your feet was transparent. Imagine also that you could remove the atmosphere. Imagine that you could see every artificial satellite position orbiting around the Earth. Then, imagine fixing your eyes to Polaris and speeding up time. If this takes a lot of imagination, the following animation might help you to visualise the scene.
Does it look like lots of bees buzzing around? Many people don’t realise this, but there are thousands of artificial satellites orbiting the Earth. Most of them can’t be seen with the unaided eye but others are clearly visible and if you don’t know what you are looking at, you could mistake it for an airplane.
What are those static satellites on that ring shape?
They are geosynchronous satellites. They rotate around the Earth at the same speed as the Earth, which means they would seem fixed in the sky. But don’t try to find them, you won’t be able as they are 35,786 kms above Earth’s surface. That’s how high a satellite has to be in order to keep the rotating period of 24h and avoid falling to the Earth because of gravity.
And the rest?
The rest of the satellites are situated at what are called Low Earth Orbit (LEO), Medium Earth Orbit (MEO) and High Earth Orbit (HEO). The closer a satellite is orbiting to the Earth, the faster it has to travel in order to counteract gravitational effect and avoid spinning into the atmosphere and disintegrate.
Have you spotted those satellites that look like carriages of a train?
They are satellites from the Starlink constellation. A communication satellite network under construction by SpaceX of small satellites in the Low Earth Orbit (LEO). The reason why they are so close to one another is because they have been launched recently and haven’t yet spread around their orbit. SpaceX plans to put 42,000 of them into the sky, creating a mesh around the Earth to provide Internet service in almost any location in the world.
The International Space Station (ISS) is the brightest of all the artificial satellites, because it is orbiting at an altitude of only 400km and is huge, with dimensions of 73 m by 109 m. Being at that altitude means that it travels at 7.6 kilometres per second. Last night it was visible around 23:05h GMT+1 in the north of Spain and I was lucky enough to have a clear sky so I managed to take the photo below with a 700mm lens attached to my camera, handheld.
It might not be the best picture ever, but it amazes me that in that bright spot that you can see with the naked eye, there are 3 people living on it right now. On May 27th, two astronauts will take off on a SpaceX Crew Dragon spacecraft to join them. It will be the first manned mission by SpaceX.
