Why can't we see evidence of alien life?

Name: Why can't we see evidence of alien life?
Duration: 5 min 54 s
Channel: Chris Anderson

Chris Anderson · TED

Credits and licence

From: Why can't we see evidence of alien life?, TED (at TED)
Licence: CC BY-NC-ND 4.0, as TED states it. Non-commercial use only, and no changed versions.
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Who can watch: Tweens profiles and older. How courses are placed