Synopsis: “Report on Planet Three” is a science fiction short story by British writer Arthur C. Clarke, published in May 1959 in Holiday magazine. Presented as an ancient Martian document, it describes the scientific observations made by astronomers on the red planet about Earth, its mysterious neighbor. Using data obtained with advanced instruments, they analyze its dense atmosphere, vast oceans, high gravity, and extreme climate, assessing whether it could support life. Clarke uses irony to offer a subtle critique of the anthropocentric view with which we tend to judge other worlds.
Report on Planet Three
By Arthur C. Clarke
(Cuento completo)
[The following document, which has just been deciphered for the Interplanetary Archaeological Commission, is one of the most remarkable that has yet been discovered on Mars, and throws a vivid light upon the scientific knowledge and mental processes of our vanished neighbors. It dates from the Late Uranium (i.e., final) Age of the Martian civilization, and thus was written little more than a thousand years before the birth of Christ.
The translation is believed to be reasonably accurate, though a few conjectural passages have been indicated. Where necessary, Martian terms and units have been converted into their terrestrial equivalents for ease of understanding.—TRANSLATOR.]
The recent close approach of the planet Earth has once again revived speculations about the possibility of life upon our nearest neighbor in space,. This is a question which has been debated for centuries, without conclusive results. In the last few years, however, the development of new astronomical instruments has given us much more accurate information about the other planets. Though we cannot yet confirm or deny the existence of terrestrial life, we now have much more precise knowledge of conditions on Earth and can base our discussions on a firm scientific foundation.
One of the most tantalizing things about Earth is that we cannot see it when it is closest, since it is then between us and the Sun and its dark side is therefore turned toward us. We have to wait until it is a morning or evening star, and thus a hundred million or more miles away from us, before we can see much of its illuminated surface. In the telescope, it then appears as a brilliant crescent, with its single giant Moon hanging beside it. The contrast in color between the two bodies is striking; the Moon is a pure silvery-white, but the Earth is a sickly blue-green. [The exact force of the adjective is uncertain; it is definitely unflattering. ‘Hideous’ and ‘virulent’ have been suggested as alternatives.—TRANSLATOR.]
As the Earth turns on its axis—its day is just half an hour shorter than ours—different areas of the planet swing out of darkness and appear on the illuminated crescent. By carrying out observations over a period of weeks, it is possible to construct maps of the entire surface, and these have revealed the astonishing fact that more than two-thirds of the planet Earth is covered with liquid.
Despite the violent controversy that has raged over this matter for some centuries, there is no longer any reasonable doubt that this liquid is water. Rare though water now is upon Mars, we have good evidence that in the remote past much of our planet was submerged beneath vast quantities of this peculiar compound; it appears, therefore, that Earth is in a state corresponding to our own world several billion years ago. We have no way of telling how deep the terrestrial ‘oceans’—to give them their scientific name—may be, but some astronomers have suggested that they are as much as a thousand feet in thickness.
The planet also has a very much more abundant atmosphere than ours; calculations indicate that it is at least ten times as dense. Until quite recently we had no way of guessing the composition of that atmosphere, but the spectroscope has now solved this problem—with surprising results. The thick gaseous envelope surrounding the Earth contains large amounts of the poisonous and very reactive element oxygen, of which scarcely a trace exists in our own air. Earth’s atmosphere also holds considerable quantities of nitrogen and water vapor, which forms huge clouds, often persisting for many days and obscuring large areas of the planet.
Being some 25 per cent nearer the Sun than Mars, Earth is at a considerably higher temperature than our world. Readings taken by thermocouples attached to our largest telescopes reveal intolerable temperatures on its Equator; at higher latitudes, however, conditions are much less extreme, and the presence of extensive icecaps at both poles indicates that temperatures there are often quite comfortable. These polar icecaps never melt completely, as do ours during the summer, so they must be of immense thickness.
As Earth is a much larger planet than Mars (having twice our diameter), its gravity is a good deal more powerful. It is, indeed, no less than three times as great, so that a 170-pound man would weigh a quarter of a ton on Earth. This high gravity must have many important consequences, not all of which we can foresee. It would rule out any large forms of life, since they would be crushed under their own weight. It is something of a paradox, however, that Earth possesses mountains far higher than any that exist on Mars; this is probably another proof that it is a young and primitive planet, whose original surface features have not yet eroded away.
Looking at these well-established facts, we can now weigh the prospects for life on Earth. It must be said at once that they appear extremely poor; however, let us be open-minded and prepared to accept even the most unlikely possibilities, as long as they do not conflict with scientific laws.
The first great objection to terrestrial life—which many experts consider conclusive—is the intensely poisonous atmosphere. The presence of such large quantities of gaseous oxygen poses a major scientific problem, which we are still far from solving. Oxygen is so reactive that it cannot normally exist in the free state; on our own planet, for example, it is combined with iron to form the beautiful red deserts that cover so much of the world. It is the absence of these areas which gives Earth its unpleasant greenish hue.
Some unknown process must be taking place on Earth which liberates immense quantities of this gas. Certain speculative writers have suggested that terrestrial life forms may actually release oxygen during the course of their metabolism. Before we dismiss this idea as being too fanciful, it is worth noting that several primitive and now extinct forms of Martian vegetation did precisely this. Nevertheless, it is very hard to believe that plants of this type can exist on Earth in the inconceivably vast quantities which would be needed to provide so much free oxygen. [We know better, of course. All the Earth’s oxygen is a by-product of vegetation; our planet’s original atmosphere, like that of Mars today, was oxygen-free.—TRANSLATOR.]
Even if we assume that creatures exist on Earth which can survive in so poisonous and chemically reactive an atmosphere, the presence of these immense amounts of oxygen has two other effects. The first is rather subtle, and has only recently been discovered by a brilliant piece of theoretical research, now fully confirmed by observations.
It appears that at a great altitude in the Earth’s atmosphere—some twenty or thirty miles—the oxygen forms a gas known as ozone, containing three atoms of oxygen as compared with the normal molecule’s two. This gas, though it exists in very small quantities so far from the ground, has an overwhelmingly important effect upon terrestrial conditions. It almost completely blocks the ultraviolet rays of the Sun, preventing them from reaching the surface of the planet.
This fact alone would make it impossible for the life forms we know to exist on Earth. The Sun’s ultraviolet radiation, which reaches the surface of Mars almost unhindered, is essential to our well-being and provides our bodies with much of their energy. Even if we could withstand the corrosive atmosphere of Earth, we should soon perish because of this lack of vital radiation.
The second result of the high oxygen concentration is even more catastrophic. It involves a terrifying phenomenon, fortunately known only in the laboratory, which scientists have christened ‘fire.’
Many ordinary substances, when immersed in a atmosphere like that of Earth’s and heated to quite modest temperatures, begin a violent and continuous chemical reaction which does not cease until they are completely consumed. During the process, intolerable quantities of heat and light are generated, together with clouds of noxious gases. Those who have witnessed this phenomenon under controlled laboratory conditions describe it as quite awe-inspiring; it is certainly fortunate for us that it can never occur on Mars.
Yet it must be quite common on Earth—and no possible form of life could exist in its presence. Observations of the night side of Earth have often revealed bright glowing areas where fire is raging; though some students of the planet have tried, optimistically, to explain these glows as the lights of cities, this theory must be rejected. The glowing regions are much too variable; with few exceptions, they are quite short-lived, and they are not fixed in location. [These observations were doubtless due to forest fires and volcanoes—the latter unknown on Mars. It is a tragic irony of fate that had the Martian astronomers survived a few more thousand years, they would have seen the lights of man’s cities. We missed each other in time by less than a millionth of the age of our planets.—TRANSLATOR.]
Its dense, moisture-laden atmosphere, high gravity, and closeness to the Sun make Earth a world of violent climatic extremes. Storms of unimaginable intensity have been observed raging over vast areas of the planet, some of them accompanied by spectacular electrical disturbances, easily detected by sensitive radio receivers here on Mars. It is hard to believe that any form of life could withstand these natural convulsions, from which the planet is seldom completely free.
Although the range of temperatures between the terrestrial winter and summer is not so great as on our world, this is slight compensation for other handicaps. On Mars, all mobile life forms can easily escape the winter by migration. There are no mountains or seas to bar the way; the small size of our world—as compared with Earth—and the greater length of the year, make such seasonable movements a simple matter, requiring an average speed of only some ten miles a day. There is no need for us to endure the winter, and few Martian creatures do so.
It must be quite otherwise on Earth. The sheer size of the planet, coupled with the shortness of the year (which only lasts about six of our months), means that any terrestrial beings would have to migrate at a speed of about fifty miles a day in order to escape from the rigors of winter. Even if such a rate could be achieved (and the powerful gravity makes this appear most unlikely), mountains and oceans would create insuperable barriers.
Some writers of science fiction have tried to get over this difficulty by suggesting that life forms capable of aerial locomotion may have evolved on Earth. In support of this rather far-fetched idea, they argue that the dense atmosphere would make flying relatively easy; however, they gloss over the fact that the high gravity would have just the reverse effect. The conception of flying animals, though a charming one, is not taken seriously by any competent biologist.
More firmly based, however, is the theory that if any terrestrial animals exist, they will be found in the extensive oceans that cover so much of the planet. It is believed that life on our own world originally evolved in the ancient Martian seas, so there is nothing at all fantastic about this idea. In the oceans, moreover, the animals of Earth would no longer have to fight the fierce gravity of their planet. Strange though it is for us to imagine creatures that could live in water, it would seem that the seas of Earth may provide a less hostile environment than the land.
Quite recently, this interesting idea has received a setback through the work of the mathematical physicists. Earth, as is well known, has a single enormous moon, which must be one of the most conspicuous objects in its sky. It is some two hundred times the diameter of even the larger of our two satellites, and though it is at a much greater distance its attraction must produce powerful effects on the planet beneath it. In particular, what are known as ‘tidal forces’ must cause great movements in the waters of the terrestrial oceans, making them rise and fall through distances of many feet. As a result, all low-lying areas of the Earth must be subjected to twice-daily flooding; in such conditions it is difficult to believe that any creatures could exist either in land or sea, since the two would be constantly interchanging.
To sum up, therefore, it appears that our neighbor Earth is a forbidding world of raw, violent energies, certainly quite unfitted for any type of life which now exists on Mars. That some form of vegetation may flourish beneath that rain burdened, storm-tossed atmosphere is quite possible; indeed, many astronomers claim to have detected color changes in certain areas which they attribute to the seasonal growth of plants.
As for animals—this is pure speculation, all the evidence being against them. K they exist at all, they must be extremely powerful and massively built to resist the high gravity, probably possessing many pairs of legs and capable only of slow movement. Their clumsy bodies must be covered with thick layers of protective armor to shield them from the many dangers they must face, such as storms, fire, and the corrosive atmosphere. In view of these facts, the question of intelligent life on Earth must be regarded as settled. We must resign ourselves to the idea that we are the only rational beings in the Solar System.
For those romantics who still hope for a more optimistic answer, it may not be long before Planet Three reveals its last secrets to us. Current work on rocket propulsion has shown that it is quite possible to build a spacecraft that can escape from Mars and head across the cosmic gulf toward our mysterious neighbor. Though its powerful gravity would preclude a landing (except by radio-controlled robot vehicles), we could orbit Earth at a low altitude and thus observe every detail of its surface from little more than a millionth of our present distance.
Now that we have at last released the limitless energy of the atomic nucleus, we may soon use this tremendous new power to escape the bonds of our native world. Earth and its giant satellite will be merely the first celestial bodies our future explorers will survey. Beyond them lie …
[Unfortunately, the manuscript ends here. The remainder has been charred beyond decipherment, apparently by the thermonuclear blast that destroyed the Imperial Library, together with the rest of Oasis City. It is a curious coincidence that the missiles which ended Martian civilization were launched at a classic moment in human history. Forty million miles away, with slightly less advanced weapons, the Greeks were storming Troy.—TRANSLATOR.]
THE END
