content: I think there is comfort in the thought. Do you really want to think about a species that has the intelligence for interstellar travel? We can barely make it to the moon and back. Look at how we have stripped this planet of major resources and treat wild animals. Now think about a species that has found out how to do interstellar space travel but hasn't mastered recycling. They jump from planet to planet taking resources; Lower life forms are in the way.