DWARFED BY A GIANT: The Cassini spacecraft, currently exploring the Saturnian system, caught a glimpse of Earth in 2006 at a distance of about 1.5 billion kilometers. The planet is visible as a bright dot above and to the left of Saturn's main rings. (In the detail above left, Earth's moon is just visible as a hazy mass to the planet's left.) Ordinarily the sun's glare would be too bright for Cassini to look back at its home world, but the spacecraft took advantage of a position in which Saturn stood between the probe and the sun to sneak a peek at Earth.~ NASA/JPL/Space Science Institute
PALE BLUE DOT: As the Voyager 1 spacecraft roamed ever deeper into the solar system, astronomer Carl Sagan thought it would be worthwhile to have the NASA probe take a look back at Earth before the planet receded completely from view. "Our planet would be just a point of light, a lonely pixel, hardly distinguishable from the many other points of light Voyager could see, nearby planets and far-off suns," Sagan recalled in his 1994 book Pale Blue Dot. "But precisely because of the obscurity of our world thus revealed, such a picture might be worth having." In 1990 he got his wish: Voyager 1 turned to see the lonely pixel (0.12 pixel, actually), photographing Earth from six billion kilometers away.~ NASA
