DISTANCE AND SIZE
Saturn is almost twice as far from the sun as Jupiter, and between nine and ten times farther than we are. His mean distance from the sun is eight hundred and eighty-seven million miles; but his distance varies nearly one hundred million miles between perihelion and aphelion. His orbit is only a trifle more eccentric than that of Jupiter, but the variation in miles is so much greater because the orbit is so much larger.
His average distance from the earth at opposition is seven hundred and ninety-four million miles, but at the most favorable opposition it may be fifty million miles nearer than that. At conjunction his average distance is nine hundred and eighty million miles; but his greatest possible distance at such times may be as much as one billion miles. When he is in this situation it takes light a little more than an hour and a half to pass from him to us. At his nearest we receive light from him in about an hour and six minutes. At his average distance from the sun, light requires about an hour and twenty minutes to go from one to the other.
While Saturn is next to Jupiter in size among the planets, he is not as large as Jupiter by two-thirds, but his mass is almost three times greater than that of all the other planets put together except Jupiter. It is ninety-five times greater than that of the earth. In diameter Saturn is 72,772 miles; but it is more flattened at the poles than any other planet, and in consequence there is a difference of nearly seven thousand miles between its polar and its equatorial diameters.
The density of Saturn is less than that of any other planet, and it is ten times less than that of the earth. No other planet is less dense than water; but Saturn would float in water, and is not more dense than cork. On account of its mass its gravity is greater than that of the earth by about one-tenth. This is not enough to make a very interesting difference in the weight of objects on Saturn and on the earth. The average person weighing one hundred and fifty pounds here would weigh only one hundred and sixty-five pounds on Saturn. The numerous penny-in-the-slot weighing-machines vary almost that much. Saturn has eighty-three times more surface than the earth, and more than seven hundred and fifty times the earth’s volume.