Darkness in the open air.   When all things familiar are invisible and forgotten, how do you keep your eyes from the brilliant sky above? You stare in awe. Thousands of stars surround you, ancient, intangible, light from a world far beyond anything your senses were built for.   In the darkness, your dreams come alive.   The dreaming first took the form of stories.   The dark patches against the brilliant center of the Galaxy, in the Andes became a lama who, tired from the journey, drifted down to drink water from the crystal lakes of the high plateau....

What's that bright star over there? Just an ordinary question by a Twitter follower, one might think. But it wasn't. The question was asked by a professional astronomer a couple of years ago at an astronomy conference in the Netherlands. In fact it was a planet, Saturn, visible high in the spring sky.

Our interplanetary emissaries – spacecraft we send to explore the Solar System – occasionally turn their gaze back at Spaceship Earth from the Moon, Mercury, Mars, Saturn, and beyond. Apollo 8’s iconic Earthrise was one of Earth’s first family portraits, with Earth rising above the lunar horizon. In Voyager’s Pale Blue Dot , proposed and made famous by Carl Sagan, Earth is nothing but a single pixel of color with no hint of features or inhabitants. Humbling, awe-inspiring, thought-provoking, these images strike a chord with all of humanity.