Pale Blue Dot
See that pale blue dot in the pic below? That’s earth as seen from Saturn (900 million miles away), taken by the Cassini spacecraft. And guess what: “It's very difficult to capture pictures of the Earth from this distance because we're so relatively close to the Sun.” When alive, Carl Sagan hoped such a pic might be taken by Voyager. What he wrote in “Pale Blue Dot: A Vision of the Human Future in Space” would apply just as much to the Cassini pic: “Our planet would be just a point of light, a lonely pixel hardly distinguishable from the other points of light Voyager would see: nearby planets, far off suns. ” Why the desire? “It had been well understood by the scientists and philosophers of classical antiquity that the Earth was a mere point in a vast, encompassing cosmos—but no one had ever seen it as such. ” But more importantly: “There is no sign of humans in this picture: not our reworking of the Earth's surface; not our machines; not ourselves. Fr...