152 | The Sky 
(four of which are visible through a small telescope). Ju- 
piter’s surface is fluid, the fluid being composed for the most _ 
part of various gases liquefied because of the low tempera- 
ture (about —270° F). Great colored streaks covering the 
surface parallel to the equator are by far the most conspicu- 
ous feature of a telescopic view of the planet. 
SATURN, THE RINGED ONE 
Next in order of distance from the sun is Saturn, slightly 
smaller in size than Jupiter, but chiefly remarkable because 
of its three rings, two of which are very bright and easily vis- 
ible through a small telescope. The third ring, the innermost 
“crepe ring, is much more difficult to observe. No number 
of drawings or models or photographs of Saturn can convey — 
the feeling of awe and wonder that comes over the observer 
as he takes his first telescopic look at Saturn’s rings. Even 
though he knows what to expect, you will hear him mutter 
to himself something like: “Well, ITl be damned!” 
THE OUTERMOST PLANETS 
Uranus, Neptune and Pluto are the outermost planets of 
mectlaaas 
the solar system. Before the last two had been actually ob- — 
served, their existence was deduced from variations in the or- — 
bits of some of the planets which could only be produced by ~ 
the influence of other planets. 
Beyond Saturn, and slightly less than half its size, is Uranus 
with its four satellites. As seen in a telescope, Uranus is sea- — 
green in color. It is so remote in space that it is barely visible — 
to the naked eye. Uranus rotates on its axis in 10.7 hours and 
takes about 84 of our years to See its revolution around 
the sun. 
Although Neptune is the third largest of the planets, it is 
