Some Scientists Are Worried About Aliens

For centuries, humans have gazed out at the stars and wondered about the possibility of intelligent life on other worlds.

Who’s to say that someone or something isn’t sitting on another planet and wondering the same thing about Earth? Several prominent scientists, including Stephen Hawking, think that we’re not doing ourselves any favors by broadcasting our location to other – potentially hostile – civilizations.

But a plan is in place to cloak our planet’s presence from other beings. Yes, really. ABC’s Jim Ryan explains.