Space X—the American technology company—launched 60 satellites into space in January 2020. Space X
plans to create a network of 12,000 satellites. The company says that the network, known as Starlink, will help
provide better Internet service to remote parts of the world. But astronomers say the growing number of satellites
orbiting the Earth is making it harder for them to observe and learn from the universe.
Satellites are made of metal that reflects sunlight. This makes them show up in the night sky as bright,
slow-moving dots. After the launch, the Starlink satellites appeared in images taken by telescopes and deep-space
cameras as a line of bright lights flying across the sky. Astronomers learn about space by using large telescopes
and special cameras to observe light coming from very far away. The information they collect can help them
understand things like how galaxies are formed or which planets might be able to support life.
Some astronomers also use radio telescopes, which record radio waves coming from space. This makes it
possible to study things that give off low energy and would not show up as light—like dust and gases. In April
2019, astronomers used information collected by several radio telescopes to produce the first image of a black
hole. Large groups of satellites—known as “satellite constellations”—give off radio signals of their own and
reflect radio waves coming from Earth. These extra signals interfere with radio waves coming from further away
in the galaxy. While it might be possible to build satellites with surfaces that don’t reflect light, it will be very
difficult to make satellites that don’t interfere with radio waves.