Dreams of an Astronomer

CHAPTER I. A Voyage in the Sky

A VOYAGE IN THE SKY

INTRODUCTION

IT WAS at Venice. The lofty windows of the ancient Ducal Palace of the Speranzi opened upon the Grand Canal. The orb of night was mirrored in the waters by a furrow of silver spangles, and the immensity of the sky stretched over the towers and cupolas.

When the musicians borne by the gondolas had turned the corner of the canal to glide towards the Bridge of Sighs, their last choruses vanished in the night, and Venice seemed to go to sleep in that profound silence known to no hive of humanity but the Queen of the Adriatic. This Venetian silence was untroubled save by the cadenced beats of the old clock, and perhaps I should not have appreciated the whole depth of the universal muteness but for the regular oscillation of that apparatus designed for measuring time. The continuous “tick-tock” marked out the silence, and, curiously enough, seemed to intensify it.

Seated in the embrasure of the high window, I contemplated the shining disc of the Moon enthroned in an azure sky filled entirely with its light, and I remembered that this luminary of the night, so tranquil and calm in appearance, moved a thousand yards in space at each beat of the clock. This fact struck me for the first time with a certain force, perhaps on account of the enveloping solitude.

Gazing upon the lunar globe, in which I could distinguish with the naked eye the ancient seas and geographical outlines, I bethought myself that it was still perhaps inhabited by beings organised differently from ourselves who can live in an extremely rarefied atmosphere; but what struck me even more forcibly was its rapid revolution round the Earth, at the rate of 1,000 yards at each beat of the clock, making 38 miles a minute, 2,280 an hour, 53,800 a day, or 1,500,000 miles for each lunar month.

I saw in my mind the Moon revolving round us from west to east in less than a month, and at the same time I felt, so to speak, the daily movement of the Earth about its axis, also from west to east, which makes the sky appear to move in the opposite direction. While I was still reflecting, indeed, the Moon had actually shifted and descended in the west towards the steeple of the Chiesa. These terrestrial and celestial movements, softer than those of the gondolas gliding on the limpid waters, bear us along through reality as through a dream. They measure the days and the years as we pass, like fleeting shadows, while they endure for ever. The silent Moon, sphinx of the sky, shone already on the waters silvered by her splendour millions of years ago, while terrestrial humanity was still awaiting its slow unfolding in the limbo of future possibilities. Strange animals peopled the forests which covered the continents, fantastic fishes pursued each other in the floods, vampires clove the air, and two-footed crocodiles, which seem to be the ancestors of those of Egyptian mythology, showed themselves in the clearings on the banks of the rivers. Later the same Moon shone on the birth of the flowers, on the nests of the first birds. But how many nights had she not illuminated with pale beams before the first glance from a human eye fell upon her, before the first human thought ascended towards her! To-night she shines upon a populous and active humanity, flourishing cities, marble palaces, built amid the clouds. Just now, at my feet, in a gondola a pair of lovers called upon her to witness their eternal vows, forgetting that her rapid phases are the symbol of our changefulness and our shortness of life. Yes, she has been the confidante of many mysteries, and for a long time yet will radiant youth sing under her sky its eternal song of love. But one day, a poor, enfeebled lamp, she will only shine upon a cemetery of ice; there will be no more clocks for measuring hours nor human beings to count them. Thus I mused, in the bright moonlight which seemed to intensify all the shadows and to deepen all the abysses between the palaces plunging into the black water. This neighbouring world exists at a distance of 240,000 miles from us. Our thoughts fly thither in a flash. With the speed of light, the distance is covered in 1⅓ second. In imagination I took flight up to the distant luminary. I forgot Venice, the Adriatic, and the Earth, and I felt myself carried beyond the confines of the terrestrial atmosphere.

(1) TWO HUNDRED AND FORTY THOUSAND MILES FROM THE EARTH

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.

Here, said I to myself, is the planet of greatest interest to ourselves, the one we know best. It gravitates round the sun along an orbit traced at a mean distance of 143 million miles from the central luminary. Our Earth passes through its annual revolution at a distance of 92 million miles. There are, therefore, on an average, 51 million miles between the two orbits. On the night of my vigil, Mars happened to be at its minimum distance from the Earth. Fortunately, as the two orbits are neither circular nor parallel, the real distance is sometimes reduced to 37 million miles. Light, which takes 1⅓ second to traverse the distance between the Earth and the Moon, takes 200 seconds, or 3 minutes 20 seconds, to cross the celestial abyss which separates Mars from the Earth, It seemed to me that I really spent those 3 minutes in flying the distance, and I entirely forgot the high window of my Venetian palace over the aspect of the new world to which the flight of my thought had brought me.

(2) THIRTY-SEVEN MILLION MILES PROM THE EARTH

It is not very far, astronomically speaking. It is, in fact, quite near, a few paces away. The world of Mars is the first station of the solar system, the first planet we meet on leaving the Earth to visit the remote regions of the heavens. The farther we move away from the Earth, the smaller grows the apparent size of our own world. Seen from the Moon, our planet hangs in the sky like an enormous moon, four times the size of our own satellite, and sixteen times as luminous, for it is isolated in space and reflects the light received from the Sun, as is done by the Moon and the various planets of the solar system. From about 250,000 miles, therefore, the Earth still appears of a considerable size, being about four times the size of the full Moon. At 2½ million miles it appears ten times smaller in diameter, but still shows a perceptible disc. At the distance of the orbit of Mars, at the time when the planets are in greatest proximity (37 million miles), the Earth no longer shows a sensible disc, but is still the biggest and brightest star in the entire heavens. The inhabitants of Mars, therefore, admire us as a brilliant star in the sky, showing aspects similar to those which Venus shows to us. We are their morning and evening star, and no doubt their mythology has erected altars to us.

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