Chet Raymo, "Icon"

"Icon"
by Chet Raymo

"From NASA's Goddard Space Flight Center comes this stunning composite photograph of Earth, the sharpest "blue-dot" picture yet. Here is the planet that two thousand years ago the boldest of thinkers could imagine only in their mind's eye. Here is the watery sphere that Columbus and Magellan kept fixed in their imagination as they launched their tiny craft into the wet unknown. The blue-white planet, dappled with ocher and green, suspended in the vast - perhaps infinite -- black of space. Almost perfectly round and smooth. If you wrapped a schoolroom terrestrial globe in kitchen wrap, that thin layer of plastic would be thick enough to encompass oceans and atmosphere, the deepest oceanic trench and the highest mountains. And in that gauzy layer too is all of life, teeming, photosynthesizing, respiring, copulating, thinking, dreaming.

Click image for larger size.

What is the season? Note the slight brightening around the tip of the Baja California Peninsula (click to enlarge). Here the Sun is directly overhead, exactly on the Tropic of Cancer, twenty-three-and-one-half degrees north of the equator - the summer solstice. Here in Exuma we are also exactly on the Tropic of Cancer, a bit more than two hours east of Baja; it is early afternoon on a cloudless summer day. Europe is in twilight.

Nothing in the photograph obviously reveals the presence of the human species (unless it is that perplexing straight line between the southern tips of Greenland and Hudson Bay, which must be an artifact of the photomosaic process). But lord knows we have the power to change the picture dramatically. A nuclear war could shroud the planet in obscuring smoke and dust. Global warming might change the coastlines and the amount of cloud cover. Already, it seems, we have diminished the amount of summer sea ice at the top of the globe.

As I was growing up, in every one of my parochial school classrooms, high on the wall at the front of the room, was the image of a suffering man nailed to a cross. It was there to remind us that the creator of the universe had come to Earth and died to redeem us from the sin of having been born human in a fallen world. What it more graphically instructed me is how "inhumanely" humans can behave toward each other, even to the point of hammering nails through palms. Better, I think, to have had this image of Earth hanging there at the front of the room, to remind us of the gossamer insubstantiality of life in a universe complex and wonderful beyond our knowing, and of the moral imperative of being the only creatures in the universe (that we know about) who can say "It is beautiful" and resolve to make it more so."

- http://www.sciencemusings.com/blog/2010/03/icon.html