PLANETARY SECRETS

Otago Daily Times, Issue 22612, 2 July 1935, Page 12

PLANETARY SECRETS

NEW DISCOVERIES OLD QUESTION REVIVED DOES ONLY THE EARTH HOLD LIFE? Some billions of years ago a colossal star swam into our part of the heavens. It drifted near our'sun, and by the sheer gravitational power of its mass pulled out of the sun long streamers of gas. The wanderer passed on. The streamers shrivelled into globes that became our planets. So runs the prevailing theory of the solar system’s origin (writes Waldemar Kaempffert in the New York Times). The odds are a hundred million to one against such an encounter. Hence Eddington remarks: “ The solar system is not a typical product of the development of a star; it is not even a common variety of development; it is a freak.” There are many reasons,to suppose that the solar system may have been created thus. Jeans has pointed ?>ut that “the long filament pulled out of the sun is likely to have been richest in matter of its middle parte, these parts having been pulled out when the second star was nearest and its gravitational pull the strongest.” String the planets in a line biit preserve their relative distances from one another, draw a line round them, and you have a cigar. In the middle of the cigar are Jupiter and Saturn, the two largest planets. If we pursue the inquiry in Eddington’s frame of mind we find that each one of the planets in the system is in its turn a freak. No two have identical sizes and masses or identical lengths of day and night, or identical atmospheres, or axes tilted at identical angles. Despite their common origin, the planets differ far more than do the children of the same family. LIFE HANGS BY A THREAD.

It is because of the uniqueness of the solar system and the uniqueness of the earth that life is a precarious, exciting cosmic adventure. It literally hangs by a thread. Tilt the axis of the earth so that it assumes a new angle to the elliptic, lengthen or shorten the day or year materially, rob the atmosphere of its oxygen and water vapour, change the globular mass and therefore the attraction of gravitation or greatly increase or decrease the distance from the sun, and every plant and animal perishes.

A combination of a dozen known conditions and perhaps many more that are not known made it possible for the first bit of protoplasmic ooze to become animate, reproduce itself, and, what is more, evolve through the sponge, fish, reptile, bird and mammal into Buddha, Leonardo, and Beethoven. The many essentials of life are so remarkably inter-related that it seems as if being alive cannot be fortuitious, as if it is the very purpose of Nature to experiment with a thousand million stars to produce one little world for the creation of protoplasm capable of evolving into a myriad organic forms. All tins is borne in upon us by the recent discoveries that have been made about the atmospheres of the major planets. The astrophysicist with the aid of his spectroscope transports himself through millions of miles to worlds incredibly terrifying and beautiful. Here, for example, are Drs Sjlipher, Adel, and Wildt in different parts of America and Europe piecing together the story of Jupiter, Saturn, and Uranus, and here Drs Walter S. Adams and Theodore Dunham, of Mount Wilson, revealing new facts about Venus. INCREDIBLE WORLDS.

Such work docs much to dispel the notion that Jupiter is still red hot after a separation from the sun that must have occurrred 5,000,000.000 years ago. Rod heat implies a temperature so high that ammonia and methane would be decomposed. Their bands and lines ivould not appear in the rainbows that have been studied.

So, two new worlds are visualised. They have cores like the earth’s —heavy, dense, solid lumps of rock or nickel-iron. Outside is a thick layer of ice under high pressure. Above that a highly-compressed atmosphere with much hydrogen and ammonia and methane. Why the high pressure? Because of the known masses of the two planets. The clutch of gravitation upon them ig more powerful than on earth. On Jupiter a man would find it difficult to lift his arm because of its weight. The earth lost most of its hydrogen long ago because of its small mass. Jupiter and Saturn retain their allotments because of their mass.

We need measurements of temperature to piece out the story. What are the findings of Pettit and Nicholson? Cold, bitter cold. , Minus 220 degrees Fahrenheit for Jupiter and minus 280 for Saturn. The cold is so intense that ammonia freezes solid. Dunham, Slipher, and Wildt independently reach the conclusion that the two great planets are wrapped in clouds of ammonia crystals. So thick are the clouds that it is impossible to see deep down to the surface of the planet, where the methane must be particularly rich. Light a match on that surface, whatever it may be, and the atmosphere would catch fire —become a roaring furnace if there were any oxygen. In fact, there would be an explosion, an instantaneous chemical combination that would yield carbon dioxide and water. The ammonia clouds send over the surfaces of the two planets and thus testify to terrific hurricanes travelling at 400 to 600 miles an hour on Saturn and at least 250 on Jupiter. Why these terrific blasts? No one knows. Our own winds are the result of the sun’s heat. But at the distance of Jupiter and Saturn the sun is so remote that it can hardly warm chilly hydrogen and solid* ammonia crystals. Here we have the chief argument of those who still believe that Jupiter and Saturn are red hot. VENUS AND MAES.

The same method of spectroscopic analysis and the same reliance on artificial atmospheres in tubes in the hands of Drs Adams and Dunham have mada it clear that the air of Venus is composed largely of carbon dioxide—the gas that froths in beer and bubbles in ginger ale. Carbon dioxide is as necessary for the support of terrestrial life as oxygen. Through some mysterious alchemy, of which we know not even the rudiments, light acting upon the carhop dioxide of our atmosphere produces green plants, and with them starches and sugars. Given green vegetation, it follows that there must be water and the necessary mineral salts to support it, with oxygen as an exhaled by-product. And plants in their turn suggest the great drama of evolution. We turn to Mars. Not so long ago physicists differed about its temperature, Dr Coblentz of the Bureau of Standards, settled all doubts with the aid of a marvellously sensitive thermo-couple only one two-hundredths of an inch in diameter. With that instrument he measured the heat received not from the planet as a whole, but from particular regions. For the South Pole in summer 15 to 50 degrees F. were the readings; for the south temperate zone at the same season 63 to 75 degrees; for the tropics at noon 65 to 85 degrees: for the north temperate zone in winter 30 to 60 degrees.

The planet proved to be warmer than the sceptics contended. Probably the Martian equator is bitterly cold at night, but no colder than New York at its wintry worst. But what of the Martian atmosphere? Water vapour and oxygen are there both prerequisites of life. Astronomical doubters once believed that the white Martian polar caps were not snow but solidified carbon dioxide. Now it is certain' that the caps are snow or hoar-frost that melts in the spring and summer and inevitably gives rise to water vapour. Dr Wright has photographed Mars at Mount Wilson with light of different colours, and discovered yellow, watery clouds floating at a height of 15,000 feet. On the other hand, Professor Henry Norris Russell, of Princeton, thinks that the red areas of Mars may be otherwise interpreted. He bids us consider the oxygen that the earth carried with it from the sun when the great creative

casastrpphe occurred. Half of the original amount is gone. We see it everywhere in the form of iron ore (mere rust), ironbearing red clays and red sandstone. Iron combines avidly with oxygen. Ultimately all our oxygen will be thus chemically removed from the atmosphere. If man is not to die gasping for breath he will Have to liberate oxygen some day from the ores, clays and rocks in which it is being imprisoned. CAN IT BE?

When we turn to the other planets we face enigmas. Mercury is so near the sun that lead would melt on its surface and water .flash into steam. Uranus and Pluto are so far off that the sun must appear like a brilliant star. Days that are no brighter than our late twilight, seasons measured by years, cold that is as intense as that which prevails on Jupiter and Saturn conjure up a vision of terrifying barrenness; So it seems that only the earth is capable of supporting the higher forms of life —the one freakish world in a freakish solar system. Can it be that Nature creates a thousand million stars and causes them to radiate their substance away in order to produce a cinder or two with just the right relation to a central sun, with just the right atmosphere and chemical conditions for the support of life? Have we here justification for man’s conceit —his deep conviction that he is the very king-pin of the universe?