Aliens

Aliens are intelligent life forms in deep space. Microbes living on, say, Enceladus, are not aliens. Aliens might be trying to communicate with us via fast radio bursts.They were first heard in 2001. Alien life needs a planet like Earth and a solar system like ours with a moon and something like Jupiter. Jupiter is a shield that protects humans from comet impacts. 1 huge impact might wipe out aliens like how an asteroid wiped off the dinosaurs.