I mean, he titled his book about it “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth”. https://en.wikipedia.org/wiki/Extraterrestrial:_The_Fi

I mean, he titled his book about it “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth”. https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Sign_of_Intelligent_Life_Beyond_Earth https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Si...