At the end of 2023, there were more than 5,000 satellites orbiting Earth, with 10s of 1000s more on the way. Although individual satellites might be invisible to the unaided eye, their collective light might already be causing a 10% brightness increase in the night sky. Large surveys like Vera Rubin will see frequent satellite trails obscuring important data. And the radio pollution is also increasing with communications satellites. What can be done to restore the sky?

It's nearly impossible to identify individual stars billions of light years away. But thanks to gravitational lensing, astronomers have identified red giant stars in a distant galaxy.