The above image is taken from a presentation that the American astronomer Carl Sagan gave during the Gifford Lectures in October 1985 at Edinburgh University. That collection of lectures is available in book format as The Varieties of Scientific Experience. Let Carl himself explain the point he was making by including this in his presentation:
Carl Sagan achieved global fame with his immensely popular thirteen-part series Cosmos broadcast in 1980. Over the past year I have been catching up with several of his books including Cosmos, Billions and Billions, The Demon-Haunted World and, of course, The Varieties of Scientific Experience. His science writing is an absolute joy to read and he succeeds so well in instilling in the reader an immense sense of awe and wonder at our own place in the universe.
Before he died prematurely in 1996, he published “Pale Blue Dot“. It contains perhaps the most well known passage from his writings. Carl Sagan was involved in many NASA missions, and in February 1990 he made a suggestion to NASA. The Voyager 1 spacecraft had come to the end of its mission of photographing some of the outer planets and was now past Neptune and was six billion kilometres from the Earth (over 40 times the distance between the Earth and the Sun). Carl asked NASA to programme Voyager 1 to turn its camera around and point it towards the Earth for one final picture.
And below you can hear Carl Sagan narrate that beautiful passage himself.