Elon need not worry about being done in by space aliens. Human tribalism armed with thousands of rockets armed with billions of megatons worth of nuclear power has been our final destiney ever since 1945. At least a half dozen times we have come within second of turning lose our demons of self-destruction.

Musk may not want to see it, but civilizations by the laws of the universe never make it far into space before the technology that launched them takes them out.