银河系包含许多星星，其中太阳系的中心是太阳。太阳通过旋转和引力形成行星和卫星，如地球的月球。科学家通过观测和研究，了解了月球的地形、火山特性和环境，推测月球上可能存在独特的生命形式。
An observer endued with an infinite range of vision, and placed in that unknown center around which the entire world revolves, might have beheld myriads of atoms filling all space during the chaotic epoch of the universe. Little by little, as ages went on, a change took place；a general law of attraction manifested itself, to which the hitherto errant atoms became obedient：these atoms combined together chemically according to their affinities, formed themselves into molecules, and composed those nebulous masses with which the depths of the heavens are strewed.These masses became immediately endued with a rotary motion around their own central point.This center, formed of indefinite molecules, began to revolve around its own axis during its gradual condensation；then, following the immutable laws of mechanics, in proportion as its bulk diminished by condensation, its rotary motion became accelerated, and these two effects continuing, the result was the formation of one principal star, the center of the nebulous mass.
By attentively watching, the observer would then have perceived the other molecules of the mass, following the example of this central star, become likewise condensed by gradually accelerated rotation, and gravitating round it in the shape of innumerable stars. Thus was formed the Nebulae, of which astronomers have reckoned up nearly 5，000.
Among these 5，000 nebulae there is one which has received the name of the Milky Way, and which contains eighteen millions of stars, each of which has become the center of a solar world.
If the observer had then specially directed his attention to one of the more humble and less brilliant of these stellar bodies, a star of the fourth class, that which is arrogantly called the Sun, all the phenomena to which the formation of the Universe is to be ascribed would have been successively fulfilled before his eyes. In fact, he would have perceived this sun, as yet in the gaseous state, and composed of moving molecules, revolving round its axis in order to accomplish its work of concentration.This motion, faithful to the laws of mechanics, would have been accelerated with the diminution of its volume；and a moment would have arrived when the centrifugal force would have overpowered the centripetal, which causes the molecules all to tend toward the center.
Another phenomenon would now have passed before the observer's eyes, and the molecules situated on the plane of the equator, escaping like a stone from a sling of which the cord had suddenly snapped, would have formed around the sun sundry concentric rings resembling that of Saturn. In their turn, again, these rings of cosmical matter, excited by a rotary motion about the central mass, would have been broken up and decomposed into secondary nebulosities, that is to say, into planets.Similarly he would have observed these planets throw off one or more rings each, which became the origin of the secondary bodies which we call satellites.
Thus, then, advancing from atom to molecule, from molecule to nebulous mass, from that to principal star, from star to sun, from sun to planet, and hence to satellite, we have the whole series of transformations undergone by the heavenly bodies during the first days of the world.
Now, of those attendant bodies which the sun maintains in their elliptical orbits by the great law of gravitation, some few in turn possess satellites. Uranus has eight, Saturn eight, Jupiter four, Neptune possibly three, and the Earth one.This last, one of the least important of the entire solar system, we call the Moon；and it is she whom the daring genius of the Americans professed their intention of conquering.
The moon, by her comparative proximity, and the constantly varying appearances produced by her several phases, has always occupied a considerable share of the attention of the inhabitants of the earth.
From the time of Thales of Miletus, in the fifth century B. C.，down to that of Copernicus in the fifteenth and Tycho Brahe in the sixteenth century A.D.，observations have been from time to time carried on with more or less correctness, until in the present day the altitudes of the lunar mountains have been determined with exactitude.Galileo explained the phenomena of the lunar light produced during certain of her phases by the existence of mountains, to which he assigned a mean altitude of 4，500 toises.After him Hevelius, an astronomer of Dantzic, reduced the highest elevations to 2，600 toises；but the calculations of Riccioli brought them up again to 7，000 toises.
At the close of the eighteenth century Herschel, armed with a powerful telescope, considerably reduced the preceding measurements. He assigned a height of 1，900 toises to the maximum elevations, and reduced the mean of the different altitudes to little more than 400 toises.But Herschel's calculations were in their turn corrected by the observations of Halley, Nasmyth, Bianchini, Gruithuysen, and others；but it was reserved for the labors of Boeer and Maedler finally to solve the question.They succeeded in measuring 1，905 different elevations, of which six exceed 2，600 toises, and twenty-two exceed 2，400 toises.The highest summit of all towers to a height of 3，801 toises above the surface of the lunar disc.At the same period the examination of the moon was completed.She appeared completely riddled with craters, and her essentially volcanic character was apparent at each observation.By the absence of refraction in the rays of the planets occulted by her we conclude that she is absolutely devoid of an atmosphere.The absence of air entails the absence of water.It became, therefore, manifest that the Selenites, to support life under such conditions, must possess a special organization of their own, must differ remarkably from the inhabitants of the earth.
At length, thanks to modern art, instruments of still higher perfection searched the moon without intermission, not leaving a single point of her surface unexplored；and notwithstanding that her diameter measures 2，150 miles, her surface equals the one-thirteenth part of that of our globe, and her bulk the one-forty-ninth part of that of the terrestrial spheroid—not one of her secrets was able to escape the eyes of the astronomers；and these skillful men of science carried to an even greater degree their prodigious observations.
Thus they remarked that, during full moon, the disc appeared scored in certain parts with white lines；and, during the phases, with black. On prosecuting the study of these with still greater precision, they succeeded in obtaining an exact account of the nature of these lines.They were long and narrow furrows sunk between parallel ridges, bordering generally upon the edges of the craters.Their length varied between ten and 100 miles, and their width was about 800 toises.Astronomers called them chasms, but they could not get any further.Whether these chasms were the dried-up beds of ancient rivers or not they were unable thoroughly to ascertain.
The Americans, among others, hoped one day or other to determine this geological question. They also undertook to examine the true nature of that system of parallel ramparts discovered on the moon's surface by Gruithuysen, a learned professor of Munich, who considered them to be“a system of fortifications thrown up by the Selenitic engineers”.These two points, yet obscure, as well as others, no doubt, could not be definitely settled except by direct communication with the moon.
Regarding the degree of intensity of its light, there was nothing more to learn on this point. It was known that it is 300，000 times weaker than that of the sun, and that its heat has no appreciable effect upon the thermometer.As to the phenomenon known as the“ashy light”，it is explained naturally by the effect of the transmission of the solar rays from the earth to the moon, which give the appearance of completeness to the lunar disc, while it presents itself under the crescent form during its first and last phases.
Such was the state of knowledge acquired regarding the earth's satellite, which the Gun Club undertook to perfect in all its aspects, cosmographic, geological, political, and moral.
infinite range of vision - 无限视野
chaotic epoch - 混沌时代
atoms - 原子
general law of attraction - 万有引力定律
errant atoms - 游离的原子
chemically - 化学地
affinities - 亲和性
molecules - 分子
nebulous masses - 星云团
rotary motion - 旋转运动
central point - 中心点
revolve - 旋转
axis - 轴
gradual condensation - 逐渐凝聚
immutable laws of mechanics - 不变的力学定律
accelerated - 加速
principal star - 主星
Nebuae - 星云
Milky Way - 银河
stellar bodies - 恒星体
gaseous state - 气态
moving molecules - 移动的分子
centrifugal force - 离心力
centripetal - 向心力
concentric rings - 同心圆
Saturn - 土星
cosmical matter - 宇宙物质
secondary nebulosities - 次级星云
planets - 行星
satellites - 卫星
Uranus - 天王星
Jupiter - 木星
Neptune - 海王星
Moon - 月球
proximity - 接近
phases - 月相
Thales of Miletus - 米利都的泰勒斯
Copernicus - 哥白尼
Tycho Brahe - 第谷·布拉赫
Galileo - 伽利略
Hevelius - 埃沃利尤斯
Riccioli - 里西奥利
Herschel - 赫歇尔
craters - 火山口
volcanic character - 火山特性
refraction - 折射
atmosphere - 大气
Selenites - 月球人
special organization - 特殊组织
diameter - 直径
surface - 表面
globe - 球体
spheroid - 扁球体
chasms - 沟槽
furrows - 沟壑
parallel ridges - 平行脊
craters - 火山口
Geological - 地质学的
Munich - 慕尼黑
Gruithisuysen - 格鲁伊修森
fortifications - 防御工事
Selenitic engineers - 月球工程师
Gun Club - 大炮俱乐部
一位目光极其敏锐的观察家，置身于宇宙围绕运转的这个未知的中心的话，就会看到无数的原子充满了宇宙混沌时期的空间。但是，随着时间的推移，渐渐地发生了一个变化：一个引力定律出现了，此前一直游离着的原子都遵守着这一定律。这些原子根据其相似性以化学的方式进行组合，构成分子，并形成模糊的星团，散布于天空深处。这些星团立刻开始围绕它们的中心点旋转起来。这个由一些模糊的分子组成的中心开始自转，同时逐渐地凝聚在一起。另外，根据力学不变定律，随着凝结所导致的体积的缩小，它的旋转速度在加快；而在这两种变化持续不断的作用下，便形成了一个主星，即模糊星团的中心。
观察家如果仔细观察，就会看到星团的其他那些分子也像主星一样，通过逐渐加速的旋转凝聚起来，形成无数的星体，围绕着主星转动。于是，星云就形成了。据天文学家统计，现在有大约五千个星云。
在这五千个星云中，有一个星云被人们称为“银河”，它包含着一千八百万颗星星，其中的每一颗星星都变成了某个太阳系的中心。
如果观察家专注于这一千八百万颗星星中最普通、最暗淡的星中的一颗四等星，也就是被人们自豪地称为“太阳”的那一颗的话，那么宇宙形成的所有现象都会相继呈现在他的眼前。其实，这个太阳还处于气体状态，由一些活动的分子组成，观察家会发现它绕着自身的轴心在旋转，最后凝聚起来。这一运动遵循着力学原理，随着体积的缩小，它的旋转速度在加快；到了某一时刻，离心力便会胜过把分子吸向中心的向心力。
这时，另一种现象就会出现在观察家的眼前：位于赤道表面的分子像投石器的绳子断了之后的石子似的纷纷飞了出去，在太阳周围形成好多土星光环似的同心圆圈。而这些宇宙物质组成的光环在围着一个中心旋转，分裂成一个个雾状星云，即行星。假如观察家集中注意力观察这些行星的话，就会发现它们产生了一个或多个宇宙物质组成的光环，这就是人们称为卫星的低级天体的起源。
因此，从原子到分子，从分子到星团，从星团到星云，从星云到主星，从主星到太阳，从太阳到行星，从行星到卫星，人们看到自宇宙初期开始天体经历的一系列演变。
被太阳通过万有引力束缚在它们的椭圆形轨道上的这些小行星，有几个也有它们自己的卫星。天王星有八个，土星有八个，木星有四个，海王星可能有三个，地球有一个。最后的这一个是整个太阳系中最微不足道的一个，名叫月球，而大胆的美国人声称要征服的正是它。
由于离我们相对而言比较近，而且它的不同的月相更替又很快，所以这个星球首先吸引了地球居民们的注意。
从公元前五世纪的米利都的泰勒斯[19]到公元十五世纪的哥白尼，到公元十六世纪的第谷·布拉赫，人们不断地进行观测工作，得出的结论或多或少是正确的，而直到今天月球上山脉的精确高度才被确定下来。伽利略根据月球上山脉的存在阐释了某些相位的光现象，他认为这些山脉的平均高度为四千五百托瓦兹[20]。在伽利略之后，但泽[21]的一位名为埃沃利尤斯的天文学家，认为这些山脉的平均高度只有两千六百托瓦兹。但是，他的同行里西奥利却认为它们的平均高度有七千托瓦兹。
十八世纪末，赫歇尔借助一台高倍天文望远镜，又将这些山脉的测量数据大大地缩减了。他认为最高的那些山脉只有一千九百托瓦兹，认为高低不平的山脉的平均高度仅四百托瓦兹而已。不过，赫歇尔还是弄错了。后来，经哈利、内史密斯、比安奇尼、格鲁伊修森等诸多天文学家的观测，特别是经过比尔先生和麦德莱先生孜孜不倦的探求，这个关于山脉的高度问题才最终得到解决。比尔先生和麦德莱先生一共测量了一千九百零五座山，其中有六座超过两千六百托瓦兹，有二十二座超过两千四百托瓦兹。其中最高的山峰以三千八百零一托瓦兹的高度俯视着月球表面。与此同时，对月球的了解变得完整了。这颗星球上遍布着火山口，它的火山特性在每一次观测中都表现得很明显。由于被它遮挡住的行星的星光并没有折射，我们可以推定，月球上几乎没有空气。没有空气，导致了水的缺失。因此，显而易见，月球人在这种条件下生存，就必须具有独特的身体结构，与地球人迥然不同才行。
总之，由于采用了新的方法，加上新的仪器又更加完善，月球被不断地探测着，它的表面没有一处未被探测到。月球的直径为两千一百五十英里[22]，表面积是地球表面积的十三分之一[23]，体积为地球这个扁球体的四十九分之一，它的任何秘密都无法逃过天文学家们的眼睛；而且，这些聪明过人的科学家将更加深入地进行惊人的观察。
通过观测，他们发现满月时，月面的某些部分会出现白色条纹；而在不同月相时，出现的则是黑色条纹。经过更加仔细而精确的研究，他们终于完全弄清楚了这些条纹的性质。这是一些狭长的沟槽，凹陷于两条平行边之间，一般来说，一直延伸至火山口的周围；它们的长度在十到一百英里之间，宽八百托瓦兹。天文学家把它们称为沟槽，不过，他们能够做到的，也只能是给它们取这么个名称。至于这些沟槽是不是从前的河流干涸后的河床，他们就说不清楚了。
因此，美国人希望有一天能弄清楚这一地质现象。他们也希望有一天能搞明白，被格鲁伊修森这位来自慕尼黑的博学的教授在月球表面上发现的一系列平行壁垒系统的真正本质。这位教授把它们看作月球工程师们所构筑的防御工事系统。这两个问题悬而未决。当然还有其他的一些问题，只有在与月球建立起直接的联系之后，才能彻底解决。
至于月光的强度，已不再有任何的疑问了。人们已经知道，月光的强度是太阳光强度的三十万分之一，而且月亮的热力对温度计不起作用；至于那个被称为“灰光”的现象，当然是太阳光射向地球后反射到月球上产生的，当月相为新月或满月的时候，“灰光”与月面呈现出的月牙形式似乎在相互辉映。
这就是目前所掌握的这颗地球卫星的情况。大炮俱乐部准备从宇宙学、地质学、政治学和伦理学等方面对之进行全面的研究。