In 1990, the Voyager 1 spacecraft photographed the planets of the solar system from outside the orbit of Pluto.   This photo shows the earth (tiny dot just left of the white line) from 4 billion miles away.  (The streaks are not real; they are caused by sunlight glare in the camera.)  Astronomer Carl Sagan wrote of this photo:

Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader", every saint and sinner in the history of our species lived there--on a mote of dust suspended in a sunbeam. ...Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. ...There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. Photo Credit:  NASA:  Visible Earth http://visibleearth.nasa.gov/view_rec.php?id=601 http://en.wikipedia.org/wiki/Carl_Sagan http://en.wikipedia.org/wiki/Pale_Blue_Dot