It is statistically unlikely that humans are the only intelligent civilization in the universe. Nothing about the nature of other species that may exist out there will be known until contact is made beyond a radio signal from space, the likes of which can really only prove the originating civilization existed at the time the message was originally sent.
Contact with extraterrestrial intelligence may occur tomorrow, in a hundred years, or never. Although according to some, it may have already happened at some point decades, if not centuries, or even millennia ago.
In any event, open and direct contact will be a high-risk scenario for humanity. It may be peaceful or hostile. Relying on the altruism of aliens and the hope that their intentions will be benign is wishful thinking. Thus, in the context of law with relation to extraterrestrial contact, we must consider moving toward identifying as one planetary species and developing a global consensus on how to respond in either scenario. Such concepts are the essence of my forthcoming book, Contact with Extraterrestrial Intelligence and Human Law.
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