Observing satellites

Can I see satellites from Earth?

Yes! You can see satellites for the same reason that we can see the Moon and planets – they reflect light from the Sun

What can I see?

International Space Station
Credit: NASA/Crew of STS-132

The International Space Station (ISS) is the biggest artificial satellite orbiting the Earth and it’s also the brightest. Its brightness varies depending on how much sunlight it reflects but it can appear to be as bright as Venus!

When you spot it, it appears to look like a star that is moving as fast as an airplane. It travels at over 27,000 km per hour and orbits the Earth 15 times a day. The ISS has been in orbit since 1998 and usually has six astronauts on board, from all over the world.

The company SpaceX started launching Starlink satellites in May 2019. The Starlink project aims to provide internet across the whole world by using over 12,000 satellites. The Starlink satellites are launched in batches arranged in a chain. When a batch is first deployed, the satellites are close together and easy to spot, parading across the sky. Over time they drift apart and are harder to spot.

Many astronomers are concerned that light pollution from more and more satellites could make it harder for them to view objects out in space. SpaceX did make some changes to their satellites to try and reduce their brightness.

How do I spot them?

You can visit spot the station to find out when’s the best time to spot the International Space Station from where you are in the world.

This website helps you find Starlink.

Many astronomy apps and software include options to help you spot artificial satellites. For example Heavens Above or Stellarium.