The more we learn about the cosmos, the more it seems possible that we are not alone. The entire galaxy is teeming with worlds, and we're getting better at listening, so the question, "Is there anybody out there?" is one we may be able to answer soon, NBC News reported.
But do we really want to know? If aliens are indeed out there, would they be friendly explorers, or destroyers of worlds?
This is a serious question no longer confined to science fiction, because astronomers are doing more than listening. Some are advocating for a beacon that would sweep across the galaxy, letting E.T. know we're home, to see if anyone comes calling. Others argue we would be wise to keep Earth to ourselves.
"There's a possibility that if we actively message, with the intention of getting the attention of an intelligent civilization, that the civilization we contact would not necessarily have our best interests in mind," says Lucianne Walkowicz, an astrophysicist at the Adler Planetarium in Chicago. "On the other hand, there might be great benefits. It could be something that ends life on Earth, and it might be something that accelerates the ability to live quality lives on Earth. We have no way of knowing."