What can you take represented by 1 pixel that encapsulates more than the pixel itself?
It is 1990 and the probe Voyager 1 is about to leave the Solar System. Astronomer Carl Sagan proposes to NASA to send a signal to the probe to turn around and capture one last photograph of its point of origin. The photo of our Blue Planet, Earth, occupies just one pixel (or even less, at 0.12 pixel, and the image is magnified so we can see that dot of light), but in that pixel are the hopes and dreams and history of more than the 5+ billion people alive on its surface at that time.
In the future, if ever humanity succeeds in leaving our planet to voyage around the Universe, this little ‘Pale Blue Dot‘ will be the most welcoming sight (hopefully) they see on their way home.
OK, so technically, the above photo is not only 1 pixel in resolution, but the Earth itself is represented by that 1 pixel.
This narrow-angle color image of the Earth, dubbed ‘Pale Blue Dot’, is a part of the first ever ‘portrait’ of the solar system taken by Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager’s great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. This blown-up image of the Earth was taken through three color filters — violet, blue and green — and recombined to produce the color image. The background features in the image are artifacts resulting from the magnification.
See the full image of Pale Blue Dot