Aliens are creatures that might live on other planets.

No one has proven that aliens exist yet.

Some people say they've seen UFOs (flying saucers).

Scientists use big telescopes to look for alien signals.

Mars is a planet where scientists are looking for tiny alien life.

Movies often show aliens with big eyes and green skin.

The universe is so big, there might be millions of alien planets.

Some UFOs turn out to be airplanes or balloons.

Aliens could look very different from humans.

We might meet aliens one day who knows?