Pioneer Saturn Encounter

by United States. National Aeronautics and Space Administration

[1]Not currently operational.

SATURN IMAGES

Saturn, called the wonder of the heavens by early astronomers, has been studied from Earth for many centuries. When Galileo first focused his telescope on Saturn in 1610, he realized that the appearance of the planet was unusual, but he never knew its real character because the power of his homemade telescope was far too low. He thought he was looking at three globes, one large and two small, which seemed to change slowly in appearance. In 1655, Huygens, after years of observing the planet, finally realized that these projections were actually a flat ring slightly separated from the main globe.

First sketch of Saturn (Galileo, 1610).

First sketch showing a division in the rings (Cassini, 1675).

In 1675, Cassini found the first breach in the supposedly solid, rigid, and opaque ring when he discovered that it was divided into two parts by a dark line, now known as Cassini’s Division. In later years he also detected some of Saturn’s moons.

First successful photograph of Saturn (Andrew Common, 1883). (Discovering the Universe, Colin A. Ronan, Copyright 1971 by Colin A. Ronan, Basic Books, Inc., Publishers, New York.)