Saturn.
Fig. 590.—Saturn.
We now come to the most curious of all the planets—Saturn, which is an immense globe surrounded by a beautiful bright ring, or rather series of rings, and attended by eight moons. He appears to possess much the same constitution as Jupiter, but enveloped in an even denser atmosphere than the latter. Saturn’s diameter is about nine times greater than the earth; he revolves on an inclined axis in about ten hours, and has seasonal alternations of unequal length. His year is about thirty of ours (10,759 days). The most striking phenomena in connection with Saturn are his rings.
Saturn’s rings are supposed to be a close agglomeration of stars, or satellites, revolving around the planet and encircling him in a belt. The rings are apparently broad and flat and thin, resembling roughly the horizon of a globe.
The globe of the planet is not exactly in the centre of the rings, which have been measured, and are approximately as below:—
Fig. 591.—Saturn’s rings at Equinox.
| Diameter of exterior ring | 169,000 | miles. |
| Diameter of interior ring | 124,000 | ” |
| Diameter of innermost ring | 100,000 | ” |
| Interval between innermost ring and Saturn | 19,000 | ” |
| Intervals between the rings | 18,000 | ” |
| Thickness of the rings | 130 | ” |
| Breadth of the rings | 37,000 | ” |
The rings were first recognised as such by Huyghens in 1659, but Galileo had remarked the curious appearance the planet presented. Cassini confirmed Huyghens’ discovery, and found that the ring was duplicated, and Mr. Ball made the same discovery. The two outermost rings are very bright, the inner ring being darker and partially transparent, for the ball of Saturn can be perceived through it.