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We should not measure our space-faring era by where footprints have been laid.... We should measure our era by how many people take no notice at all. A legacy rises to become culture only when its elements are so common that they no longer attract comment.

Neil Degrasse Tyson (2010). “The Sky Is Not the Limit: Adventures of an Urban Astrophysicist”, p.69, Prometheus Books
We should not measure our space-faring era by where footprints have been laid.... We should measure our era by how many people take no notice at all. A legacy rises to become culture only when its elements are so common