Don't let them get too close to aliens. They might get too tame to let them go into the wild again. But slowly, slowly, people have begun to latch on. Look at the stars, think that we are one measly galaxy. There are infinite planets, stars, life forms out there.
Space just keeps on going.
There are no walls. Some people say that the universe is just a ball. There is always something. It is mind boggling. So just take a look out there, think that you are looking at a minute fraction of infinity, and then look someone in the eye and tell them that we are the only things out there.