Saturn and its rings, 1980.
© National Aeronautics & Space Administration / Science & Society
This picture was taken by one of the two Voyager spacecraft launched in 1977 to explore the planets in the outer solar system. Both flew past Jupiter in 1979 and reached Saturn in late 1980 (Voyager 1) and August 1981 (Voyager 2). Saturn was first observed through a telescope by Galileo in 1610, but its rings were not identified until 1659, by Christiaan Huygens. It is a gas giant similar in atmospheric composition to Jupiter, with banded cloud formations. The origin and formation of the rings, which are composed of ice and ice-coated dust and rock, are not precisely understood, but it seems that tidal effects caused by some of Saturn's moons play a role in maintaining their structure. A shadow cast by one of Saturn's moons is visible at the very top of the picture.