The nearest stars are so far away that voyagers would need thousands of years just to report back. The true frontier for humanity is life on earth, its exploration and the transport of knowledge about it into science, art and practical affairs. Life around us exceeds in complexity and beauty anything else humanity is ever likely to encounter. The manifold ways by which human beings are tied to the remainder of life are very poorly understood, crying for new scientific enquiry and a boldness of aesthetic interpretation. Encouraging our biophilia, preserving blocks of biodiversity before they are converted to concrete skyscrapers and asphalt parking lots, is a way of enhancing the possibility that human beings will persist into the future.
Humanity seems to have been presented with an opportunity, rare in evolution, to do likewise.