312 NATURE-STUDY REVIEW 



orbits are more eccentric than those of the large planets and con- 

 sequently they cross and re-cross each others paths without any 

 conflict; seven of them cross the path of Mars and two cross the 

 path of Jupiter. 



The next planet beyond the midget worlds is great Jupiter 1,300 

 times as large as the earth. His diameter at the Equator is more 

 than 90,000 miles and it takes him 11 years, 10>^ months to go 

 once around the sun. He rotates on his own axis in a little less 

 than ten hours, but as this great planet is a gaseous body not all 

 of the parts rotate at the same speed, the Equator rotating more 

 rapidly than the poles. His days are so short and his year so long 

 that there are more than 10,000 days in one year. Jupiter has a 

 thick atmosphere, probably one thousand miles in depth, and is 

 probably a very hot planet, but not hot enough to shine except by 

 reflecting the light of the sun, and is altogether too young to be 

 the abode of life. When seen through a telescope Jupiter is a yellow 

 globe with a series of broad, dull brownish and lighter bands alter- 

 nating parallel with the Equator; on each side of the Equator are 

 two reddish brown or slatey belts, all of these belts or bands change 

 somewhat in color and form for they consist of vapor. The great 

 father of astronomy, Gallileo, discovered in 1610 through his 

 precious, but to us very crude, telescope that Jupiter had four 

 moons. These vary in size from a diameter of 2,000 to 3,550 miles 

 and are large enough to be called worlds. Our moon measures only 

 2,160 miles through. One of Jupiter's moons races around that 

 planet in 42 hours. Later astronomers with better telescopes have 

 discovered that Jupiter really has nine moons, the nearest one to 

 the great planet being only 100 miles in diameter and has the speed 

 record of moons, for it races around Jupiter in a little less than 12 

 hours. Because of his many moons, Jupiter has transits, occulations 

 and eclipses so numerous that he is a great favorite with young 

 observers who are enjoying the wonders of the telescope. 



Something more than foiu* million miles beyond great Jupiter 

 is another large planet which is perhaps the most interesting of 

 them all; this is Sattim and was the outermost world known to the 

 ancients. It is dull reddish-yellow in color and is about 740 times 

 larger than the earth, but is gaseous and therefore not so heavy 

 comparatively. It is so far from the sun that it makes its circle 

 only once in about 29>^ years. It is more than 73,000 miles through 

 and rotates on its axis in 10 hours and 14 minutes. It is so far 



