Stephen Hawking Nomadic Aliens Blog :

Stephen Hawking has been really worried lately and some might say that some of his statements have been slightly dire. He seems worried about Alien Beings and Artificial Intelligence, saying that we evolve so slowly that it could simply stomp us out. Not only does Professor Hawking believe that nomadic Aliens might turn up in our Solar System in the near future, he believes that even without Aliens beings, we are messing up our planet so bad, if we do not stop, we might have to get out.

He thinks the survival of the human race will depend its ability to find new homes elsewhere in the Universe, because there is an increasing risk that disaster will destroy Earth. Humans have not even started to explore their Cosmic neighborhood the Milky Way Galaxy. Aliens may exist in our Cosmic Neighborhood. A Non Complacent approach may be advised when trying to communicate with Nomadic Alien Beings, whose knows what their limits of Intelligence may be.