We share this planet; we share its beauty and its mystery. We share the collective experience of physical life, of human existenceliving out the seasons of nature and the seasons of our lives, from our crying opening act to our gasping curtain fall at play's end. We are the human astronauts of Spaceship Earth, andby Native American reckoningMother Earth's children. We have more in common than not, and an equal stake in what happens on and to our planet.