In 2018, a Spanish astronomer proposed that we could detect the network of satellites an alien civilization might put in orbit around their home planet.
There are a million space rocks nearby. Astronomers have only mapped about 9,700 of them.
If you find yourself away from a city, spend an hour looking up on any clear, moonless night. You’re bound to see a few brilliant “shooting stars.” These actually have nothing to do with stars: They’re meteors, and if your viewing conditions are good, you can see about seven per hour on any given night.