O' 



02 



Marvels of the Universe 



to what 50 remarkable an object can be — as, for instance, that it is a \-olcano, or a part of the true 

 globe projecting through the clouds — but no one knows what it is. It is quite certain, liowever, 

 that although it has lasted so long, it is not a fixture on the planet, for it is constantl}^ moving both 

 in longitude and latitude. In the large coloured drawing this famous object is seen much as it 

 has appeared in recent years, lying in the hollow it has made for itself in one of the dark belts. 

 Another long-enduring object in Jupiter is an outbreak of dark matter between the two chief belts 

 in the southern (upper in the drawings) hemisphere. This disturbance, which first appeared as a 

 comparatively small object in 1901, is well shown in two of M. Antoniadi's beautiful drawings. 

 It is in the same latitude as the Red Spot, and, drifting much more rapidly, overtakes 

 and, flowing round it, passes it every two years. In the first of M. Antoniadi's drawings the 

 Red Spot is seen disappearing towards the left, and in the other coming on the disc, surrounded 



by the dark material of the great 

 disturbance. 



From what we have seen, it is 

 clear that we cannot suppose Jupiter 

 to be inhabited by creatures possessing 

 animate life such as we know it on 

 earth. Its liot, and perhaps molten, 

 state renders it unfit for their abode ; 

 nevertheless Jupiter is intensely in- 

 teresting, because it illustrates so well 

 the theory of the gradual evolution 

 of worlds. We know that although 

 it is not hot enough to shine by its 

 own light, it has many points of re- 

 semblance to the Sun, and thus it 

 falls naturally into line between that 

 giant globe of fierce heat and dazzling 

 light on the one hand, and the smaller, 

 colder and more solid bodies of our 

 system, such as the Earth and Mars 

 or the " Dead World " of the Moon, 

 on the other. We can hardly doubt 

 that in the remote ages of the past 

 our own Earth was soft and plastic 

 as Jupiter is to-day, and that earlier still it was incandescent like the sun, but being so small a 

 body, it has cooled down comparatively quickly and has long been fitted to be the abode of animal- 

 and plant-hfe. 



As already mentioned, Jupiter is attended by satellites — eight are so far known, and four of these 

 were discovered b}' Galileo in 1610. These four are so bright that they can be seen with a good 

 pair of field-glasses, but the others are very faint indeed, and three of them were discovered and 

 are best studied photographically. The most remarkable of all is the outermost, found by Mr. 

 Mellotte on photographs taken at Greenwich in 1908. It is about si.xteen million miles from the 

 planet, takes between eight and nine hundred days to complete a revolution, and, like the most 

 distant satellite of Saturn, revolves in a contrary direction to that of all the others. 



In the large coloured drawing one of the satellites is seen just passing in front of the planet, 

 and the black spot to the left of it is its shadow. We should get a somewhat similar effect if we could 

 stand on our own Moon during a total solar eclipse, for the Moon's shadow would be seen as a round 

 spot passing swiftly across the surface of the Earth. The other dark spot in the drawing is another 



Jupile 



JUPITER. 



dra^ving by M. Antoniadi 

 21 hours. 57 minutes 



