I seemed to approach the pale Phœbe and to arrive suddenly above the immense chain of the lunar Apennines, which separate the “Sea of Vapour” from the “Sea of Rain,” not far from the central meridian. I recognised, just as I had so often observed them in the telescope, the amphitheatres and craters of Archimedes, Autolycus, and Aristillus, and I hovered for some time over the steep cliffs of the “Sea of Serenity.” I saw the traces of old submersions and I distinguished several craters almost obliterated by formidable land-slides. I got accustomed to this view the more rapidly for the fact that astronomical instruments have long familiarised us with this neighbouring world, and that certain details of lunar geography are better known than are many points of terrestrial geography. Those immense amphitheatres, those yawning craters, those steep-walled mountains, those deep valleys, those numerous cracks in the soil--we have studied them all and we know them. We find there the geographical result of considerable volcanic activity, craters 2 miles in depth and 60, 100, or 150 miles wide, mountain peaks 4 or 5 miles high, plains and valleys where the traces of successive selenological epochs are traceable. In the lower depths I observed the effects of a sensible atmosphere, surface changes produced over immense stretches of ground by the action of the Sun’s rays during days fifteen times as long as ours, changes of aspect due to the frost of the long lunar night and the thaw under the midday Sun, long white streaks traversing the circular plains; something like geysers in activity; short-lived plants without any terrestrial analogy--a whole world still alive, apparently in its last death-struggle. My thought and my gaze rested on the pale figure of the Earth’s satellite, and I asked myself whether there was not alive at that moment, in some ancient city at the bottom of a crater or a valley, some thinking being, with its eyes raised to the sky, contemplating the Earth where we are and asking the same question: whether any intelligent beings lived on the surface of that immense globe throning for ever over their heads, and presenting to their minds the same riddle which their abode presents to us. While I thus reflected about our neighbour in space, the orb of night had sunk in the west, and I saw at some distance from it on the left a star shining with a reddish glow, shedding rays of fire over the heavenly vault. I was not long in recognising in this ardent star our neighbour the planet Mars, and I forgot the moon over this other celestial island, the sister of our own, which has so many analogies with our planet.