Moon (satellite)

“ The telescope reveals no seas and no oceans, no lakes and no rivers. Nor is the grandeur of the moon's scenery ever impaired by clouds over her surface. Whenever the moon is above our horizon, and terrestrial clouds are out of the way, we can see the features of our satellite's surface with distinctness. There are no clouds in the moon; there are not even the mists or the vapours which invariably arise wherever water is present, and therefore astronomers have been led to the conclusion that the surface of the globe which attends the earth is a sterile and a waterless desert. ”

“ It is very rare for the Moon to disappear completely during totality, and even when involved in the deepest part of the Earth's shadow, our satellite usually remains visible to the naked eye, or, at least, to the telescope. This phenomenon is to be attributed to the fact that the portion of the solar rays which traverse the lower strata of our atmosphere are strongly refracted, and bend inward in such a manner that they fall on the Moon, and sufficiently illuminate its surface to make it visible. ”

“ Now it flashed upon me that, when the moon was at the full, she would top the valley in the direct path of my telescope's range of view. At the thought I grew exultant. I—I, little Camille, should first read aright the history of this strange satellite. The instrument that could give shape to the stars would interpret to me the composition of that lonely orb as clearly as though I stood upon her surface. ”

“ Thus you would find that the star dwindled down in brightness before the solid body of the moon had advanced far enough to shut it out. The sudden extinction of the stars demonstrates the airless state of our satellite.
There would be another insuperable difficulty in adopting the moon as a residence, even supposing that you could get there. Water is absent from its surface. We have examined every part of it, and we find no evidences of seas or of oceans, of lakes or rivers; we never see anything like clouds or mists, which are, of course, only water in the vaporous form. ”

“ The moon is a globe of quite a different order from the earth. Its want of air and water in any measure comparable with the abundance of such elements on the earth at once establishes so profound a difference between it and the earth, that we naturally relinquish the supposition that our satellite can have any resemblance whatever to the earth when considered as the abode of organized life.
But there is another planet with which, in all probability, we have much closer affinities than we have even with Mars. ”

“ The only way by which such a catastrophe can be permanently avoided is by making the satellite move as we actually find it to do. The attraction between the earth and the moon still exists, but its effect is not then shown in bringing the moon in towards the earth. The attraction has now to exert its whole power in restraining the moon in its circular path; were the attraction to cease, the moon would start off in a straight line, and recede never to return. ”

“ If the present laws of nature have operated long enough, and if there has been no external interference, then it cannot be doubted that the moon and the earth were once in immediate proximity. We can, indeed, calculate the period in which the moon must have been revolving round the earth. The nearer the moon is to the earth the quicker it must revolve; and at the critical epoch when the satellite was [Pg 543] in immediate proximity to our earth it must have completed each revolution in about three or four hours. ”

“ But a theory of this kind is of no use unless it can be shown to apply in every case; and, moreover, the change must always be in the same direction: to suppose that the moon can turn a fine day to a wet one, and a wet day to a fine morrow indiscriminately, is to make our satellite blow hot and cold with the same mouth, and so to reduce the supposition to an absurdity. If any marked connection existed between the state of the air and the aspect of the moon, it must inevitably have forced itself unsought upon the attention of meteorologists. ”

“ In our final chapter we considered the moon as a satellite, and sought to enhance popular regard for it on account of certain high functions which it performs for man’s benefit on this earth; but which are in great risk of being overlooked. We showed that, notwithstanding the moon’s occasionally useful service as a nocturnal luminary, it fills a far higher office as a sanitary agent by cleansing the shores of our seas and rivers through the agency of the tides. ”

“ Why should the projectile of the Gun Club escape that natural arrangement?
Now in elliptical orbits attracting bodies always occupy one of the foci of the ellipsis. The satellite is, therefore, nearer the body round which it gravitates at one moment than it is at another. When the earth is nearest the sun she is at her perihelion, and at her aphelion when most distant. The moon is nearest the earth at her perigee, and most distant at her apogee. ”

“ Amongst the other speculations on this subject, many ingenious men exercised themselves in guessing what service the moon has to discharge for the earth, since it was generally agreed impossible that our satellite should revolve round us merely for its own advantage, though it might perhaps in some measure be consulting its private ends ”

“ Several of the satellites of Jupiter and of Saturn are fully as large as or even larger than our Moon, but the planets themselves are so much larger than the Earth that the contrast between planet and satellite is very much greater. Our Moon, in fact, ought really to be called the Earth's companion rather than its satellite. Viewed from Venus or from Mars it would easily be seen without the telescope, forming with the Earth a beautiful double star. ”

“ It would be seen to pass through its phases, just as does our satellite, once in a lunar day or a terrestrial month, and during that cycle of phases, since 29 of our days would be occupied by it, the axial rotation would bring all the 162 features of its surface configuration into view so many times in succession. But the greatest beauty of this noble moon would be seen during the lunar night, in considering which we shall again allude to it; for when it is full-moon to the earth it is new-earth to the moon. At lunar midnight this globe of ours is fully illuminated ”

“ But this permanent and stationary tidal wave in the moon, or elsewhere, means that the satellite presents always the same face toward its planet, moving once about its orbit in the time required for one revolution upon its axis, and the tide raised by the moon upon the earth tends to produce here the result long since achieved in our satellite, to make our day and month of equal length, and to make the earth turn always the same side toward the moon. ”

“ Seated in silence and in solitude at a powerful telescope, abstracted from terrestrial influences, and gazing upon the revealed details of some strikingly characteristic region of the moon, it requires but a small effort of the imagination to suppose one’s self actually upon the lunar globe, viewing some distant landscape thereupon ”

“ The pull of the sun upon the moon is thereby lessened; the counter-pull of the earth gets the upper hand; and our satellite, drawn nearer to us by something less than an inch each year, [954] proportionately quickens her pace. Many thousands of years hence the process will be reversed; the terrestrial orbit will close in at the sides, the lunar orbit will open out under the growing stress of solar gravity, and our celestial chronometer will lose instead of gaining time. ”

“ Some reflections upon the moon considered as a world, in reference to questions of habitability, and to the peculiar conditions which would attend a sojourn on the lunar surface, have appeared to us not inappropriate. These, though instructive, are rather curious than important. More worthy of respectful consideration are the few remarks we have offered upon the moon as a satellite and a benefactor to the inhabitants of this Earth. ”

“ The telescopic appearance of the Moon is very interesting and beautiful, especially if the orb is observed when waxing and waning. As no aqueous vapour or cloud obscures the lunar surface, all its details can be perceived with great clearness and distinctness. Indeed, the topography of the Moon is better known than that of the Earth, for the whole of its surface has been mapped and delineated with great accuracy and precision. The Moon is in no sense a duplicate of its primary, and no analogy exists between the Earth and her satellite. ”

“ Generally speaking, our satellite does not disappear entirely in the Earth's cone of shadow; the solar rays are refracted round our globe by our atmosphere, and curving inward, illumine the lunar globe with a rosy tint that reminds one of the sunset. Sometimes, indeed, this refraction does not occur, owing doubtless to lack of transparency in the atmosphere, and the Moon becomes invisible. ”

“ That the moon is not a smooth sphere of matter is a fact that manifested itself to the earliest observers. The naked eye perceives on her face spots exhibiting marked differences of illumination. These variations of light and shade, long before the invention of the telescope, induced the belief that she possessed surface irregularities like those that diversify the face of the earth, and from analogy it was inferred that seas and continents alternated upon the lunar globe. ”

“ Though the moon is going round and round the earth incessantly, yet it always manages to avoid affording us a view of what is on the other side. Our satellite always directs the same face towards the earth, and we may reasonably conjecture that the other side is covered, like the side we know, with rings and other traces of former volcanoes. In this respect the moon is quite a peculiar object. The other great celestial bodies, such as the sun or Jupiter, turn round on their axes, and show us now one side and then the other, with complete impartiality. ”

“ The critical case of a moon which was as close as possible to the surface of the planet so as just to graze it, is one of peculiar interest. The moon so circumstanced would have to hurry round its vast circle in something less than three hours. If its pace fell short of that the body would fall into the planet. Were it greater, then the body would fly off into a different path altogether. If a satellite were situated at a distance from Jupiter exactly equal to the radius of the planet at its equator, then the time of revolution would be just a little more than eight hours. ”

“ And when we see a star thus pass behind the lunar disc on one side and come out again on the other side, we are virtually observing the setting and rising of that star upon the moon. If, then, the moon had an atmosphere, it is clear, from analogy to the case of the earth, that the star must disappear later and reappear sooner than if it has no atmosphere: just as a star remains too short a time below the earth’s horizon, or behind the earth, in consequence of the terrestrial atmosphere, so would a star remain too short a time behind the moon if an atmosphere surrounded that body. ”

“ Evidence is wanting of the existence of an atmosphere surrounding the Moon; no clouds or exhalations can be perceived, and no water is believed to exist on the lunar surface. Consequently there are no oceans, seas, rivers, or lakes; no fertile plains or forest-clad mountains, such as are found upon the Earth. Indeed, all the conditions essential for the support and maintenance of organic life by which we are surrounded appear to be nonexistent on the Moon. Our satellite has no seasons; its axial rotation is so slow that one lunar day is equal in length to fourteen of our days ”

“ Selenographic charts have been constructed with a perfection which equals, if it does not even surpass, that of our terrestrial maps. Photography has given us proofs of the incomparable beauty of our satellite; in short, all is known regarding the moon which mathematical science, astronomy, geology, and optics can learn about her. But up to the present moment no direct communication has been established with her. ”

“ No particular interest had been taken in our satellite since the first exploratory expeditions nearly fifty years before, when it had been determined that the moon was of no value to Earthmen, either as an outpost for colonization or a station for the production of power from the sun's rays. ”

“ It occurred to us, however, that we might add to the interest attaching to our satellite were we to regard it for a time as a world, and consider its conditions as respects fitness for habitation by beings like ourselves. The arguments against the possibility of the moon being thus fitted for human creatures, or, indeed, for any high organism, were decisive enough to require little enforcing. ”

“ It cannot, therefore, be wondered, that in former times only one journey to the moon was known to have been accomplished, which is that related by Ariosto. But nothing seems too difficult for modern science; and it is well known that, by a most ingenious invention, we have lately been enabled to walk up into our satellite with safety. As I, amongst others, have accomplished this journey, I shall give a short narrative of my adventures, for the amusement of those who have been deterred by the distance from travelling in person. ”

“ In their dilemma to account for the retrograde motions of the planets, they denominated them wanderers, stragglers, because they would not march with the "music of the spheres." In the moon theory of the tides the lunar satellite is made to pull and push at one and the same time, which is entirely at variance with the philosophy of force. ”