Launched in 1977, 25 years ago today, the Voyager 1 spacecraft's historic tour of the outer Solar System took it past Saturn in late 1980. On November 12, 1980, Voyager 1 recorded this view looking across the edge of Titan, Saturn's largest moon, from a distance of about 22,000 kilometers.

Neptune rotates once on its axis in about 16 hours. So, spaced about 4 hours apart these 4 images of the solar system's most distant gas giant cover one Neptune day. Recorded...