Aliens are real---extinction
Sarah Sloat 16, citing Stephen Hawking, CH CBE FRS FRSA, English theoretical physicist, cosmologist, and author who was director of research at the Centre for Theoretical Cosmology at the University of Cambridge, “Stephen Hawking Says We Should Hope Aliens Don't Find Us First”, https://www.inverse.com/article/14144-stephen-hawking-says-we-should-hope-aliens-don-t-find-us-first
Since 2010, Hawking has been public about his concerns that an advance alien civilization could try to kill us all. Hawking said of aliens then: “I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach.”
Hawking also said this during a Discovery Channel program: “If aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans,” he said. “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.”