“There is a fundamental reason why we look at the sky with wonder and longing—for the same reason that we stand, hour after hour, gazing at the distant swell of the open ocean. There is something like an ancient wisdom, encoded and tucked away in our DNA, that knows its point of origin as surely as a salmon knows its creek. Intellectually, we may not want to return there, but the genes know, and long for their origins—their home in the salty depths. But if the seas are our immediate source, the penultimate source is certainly the heavens… The spectacular truth is—and this is something that your DNA has known all along—the very atoms of your body—the iron, calcium, phosphorus, carbon, nitrogen, oxygen, and on and on—were initially forged in long-dead stars. This is why, when you stand outside under a moonless, country sky, you feel some ineffable tugging at your innards. We are star stuff. Keep looking up.”