.... There are several proposed answers to the question: Eart | Asgardia Space Nation
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There are several proposed answers to the question: Earth is unique, or close to it, in having life. Alternatively, large-scale interstellar travel may be impossible. Or perhaps intelligent life will inevitably destroy itself via nuclear weapons, or runaway artificial intelligence, or global warming, or something else. Another theory is that aliens are so alien we cannot even recognize them as living things. Or perhaps other civilizations are deliberately keeping us in the dark until we are ready to join the galactic community.
