Weightless, I floated looking out Endeavour’s window. Seen from orbit, the sunlit Earth really shines. Its oceans spread out, deep blue and immense. Its landforms are art, sculpted and colored by time. Outer space, on the other hand, is blacker than black, different than any black I’ve ever seen on Earth. There is nothing to compare it to, even when you are looking up at the night sky. And what struck me—the first time and every time I looked out—was how, seen from orbit, that blackness of space goes all the way down to the very edge of our planet. Here on Earth, we look up at our blue sky and it looks like it goes on forever. But it does not. From orbit, you see this incredibly thin blue line hugging the Earth’s edge. It holds all the air upon which all life on Earth depends. It is all we have between us and the vacuum of space.

I knew then, and I know now, we need to keep our eyes on our planet. We need to be Earth’s humbled guardians. I am proud of SkyTruth, and happy and committed to serve on its board, as SkyTruth helps us keep watch so we can act.