Earth as a 'Pale Blue Dot' Date: 6 Jun 1990
This iconic image was taken by NASA's Voyager 1 spacecraft from a distance of almost 4 billion miles from Earth. From Voyager's great distance, Earth is a mere point of light, less than the size of a pixel. The dot can be seen about halfway down the orange stripe on the right.
In 1990 NASA commanded Voyager to take the image across the greatest extent of space yet traveled by humanity. Coincidentally, Earth lies right in the center of a sunbeam - one of the scattered light rays that resulted from the camera being pointed so close to the sun.
Original caption is available here.