The geocentric trap: Why finding sulphur compounds isn't proof of alien life

“ EXTREME AND LIMITING ENVIRONMENTAL PARAMETERS OF LIFE The question of the existence of extraterrestrial life is one of the most important and interesting biological questions facing mankind and has been the subject of much controversial discussion and conjecture. ”

“ The Earth's present atmosphere consists of nitrogen and oxygen in addition to relatively small amounts of other gases; most of the oxygen is of biological origin. Some of the atmospheric gases, in spite of their low amounts, are crucial for life. The ultraviolet-absorbing ozone in the upper atmosphere and carbon dioxide are examples of such gases.
Significant in the search for extraterrestrial life are the data (e.g., planet's temperature) transmitted by Mariner II, which was launched from Cape Canaveral on August 27, 1962, and flew past Venus on December 14, 1962. ”

“ In fact, we do thus recognize in the spectra of Mars, Venus, and other planets, the presence of aqueous vapour in their atmosphere, despite the fact that our own air, containing also aqueous vapour, naturally renders so much the more difficult the detection of that vapour in the atmosphere of remote planets necessarily seen through our own air. Now, a distant observer examining the light of our own earth on a day when, though the air was moist, there were no clouds, would have ample evidence of the presence of the vapour of water ”

“ A primary objective of the planetary exploration program is the detection of possible extraterrestrial life. The study of the fundamental properties of living things on Earth is restricted to the type of life which has evolved and survived here. Life which has been exposed to totally different environmental conditions may have markedly different physiological characteristics. The impact of the new information obtainable from the study of extraterrestrial life upon the sciences of medicine and biology will unquestionably be of fundamental and far-reaching importance. ”

“ Would it not be unreasonable to assume that vital phenomena on other planets must be subject to exactly the same limitations that we find circumscribing them in our world? That kind of assumption has more than once led us far astray even in dealing with terrestrial conditions. It is not so long ago, for instance, since life in the depths of the sea was deemed to be demonstrably impossible. The bottom of the ocean, we were assured, was a region of eternal darkness and of frightful pressure, wherein no living creatures could exist. ”

“ Thus a rotten egg emits sulphuretted hydrogen. Sulphur occurs largely in nature, as the various insoluble sulphides of the metals. Iron, copper, zinc, lead, antimony, arsenic, &c., occur in nature combined with sulphur. These sulphides frequently have a metallic lustre, and in the majority of cases occur crystallised, [202] and also very often several sulphides occur combined or mixed together in these crystalline compounds. If they are yellow and have a metallic lustre they are called pyrites. ”

“ On the other hand, a preponderance of carbon dioxide in the Venusian atmosphere was measured which would create a greenhouse effect. The heat of the Sun would be trapped near the surface of the planet, raising the temperature to as high as 615 degrees F. If the topography were in truth relatively flat and the rate of rotation slow, the heating effect might produce winds of 400 miles per hour or more, and 7 sand and dust storms beyond Earthly experience. ”

“ What we now see is a dead worn-out planet, on which we cannot certainly trace any activity except that of heat in the past. That there is no life there now, at any rate of the kind on our own earth, we are almost certain; first, because we can nowhere find traces of water, clouds, nor even mist, and without moisture no life like ours is possible; and secondly, because even if there is, as perhaps there may be, a thin ocean of gas round the moon there is certainly no atmosphere such as surrounds our globe. ”

“ But if it has done much in the direction of satisfying man's straining and thirsting mind and his noble aspirations for knowledge, physical as to its most important particulars, it has ever laughed at man's puny efforts to wrest the great secrets of Infinitude by the help of only mechanical apparatus. While the spectroscope has shown the probable similarity of terrestrial and sidereal substance, the chemical actions peculiar to the variously progressed orbs of space have not been detected, nor proven to be identical with those observed on our own planet. ”

“ Could we ever have anticipated that a body ninety-three millions of miles away, as the sun is, or a hundred million of millions of miles distant, as a star may be, should actually prove to have been formed from the same materials as those which compose this earth of ours and all which it contains, whether animate or inanimate? Yet such is indeed the fact. We are thus, in a measure, prepared to find that the material which forms the great solar clouds may turn out to be a substance not quite unknown to the terrestrial chemist. ”

“ The possibility of the existence of extraterrestrial life raises the important question of man's being able to detect it. Research on extraterrestrial life detection is predicated on the ability to develop ways to detect it even when the living systems are based on principles entirely different from those on Earth.
The substitution of various molecules for those of known biological significance to living organisms as we know them has been investigated; the substitution of NH2 for OH in ammonia-rich environments leads to a diverse, and biologically very promising, chemistry. ”

“ Transcending even these formidable objectives of space bioscience is an objective shared by all life sciences, the discovery of nature's scheme for coding the messages contained in biological molecules. Extraterrestrial biology seeks to find not only evidence of life now present, but the vestigial chemicals of its previous existence. The ways and means have already been made available to study molecules on whose long, recorded messages is written the autobiography of evolution—the history of living organisms extending back to the beginnings of life. ”

“ Combined with metals (sulphides) , it is common in all mineral districts. Iron pyrites (FeS2) is the most abundant source of this element. Sulphates, such as gypsum, are fairly common, but have no value so far as the sulphur in them is concerned. In coal it exists as an impurity, occurring partly as a constituent of organic compounds.
Sulphur, whether free or combined with metals, forms, on burning, sulphurous oxide (SO2) , which by the action of oxidising agents and water is converted into sulphuric acid. ”

“ Sulphur is now generally regarded as emanating from the stage of intermittent lethargy of a volcano, and the sulphides of iron, copper, arsenic, zinc, selenium, etc., fall in the same category as sulphur; they are secondary, not primary, formations. In the stage further off we have the host of sulphates produced by the oxidation of the sulphur into sulphuric acid, and its subsequent reaction on the metals and earths with which it becomes associated. ”

“ This has resulted from the oxidation of the sulphur to sulphuric acid by atmospheric agency, the acid in turn attacking the lime carbonate, and forming sulphate (gypsum) . The most plausible supposition as to the origin of the sulphur-seams would appear to be that the lakes received streams of water containing calcium sulphide in solution, this calcium sulphide probably resulting from a reduction of the masses of calcium sulphate (gypsum) by the action of volcanic heat. ”

“ Irregular masses of sulphur are often found where sulphide minerals, like pyrite or galena have been decomposed in such a way as to leave the sulphur behind. The extensive beds of sulphur are usually associated with gypsum, and are thought to be the result of water, containing bituminous matter, so acting on gypsum as to remove the calcium and oxygen as lime, and leave the sulphur. Finally many waters carry sulphates in solution, from which the sulphur may be 167 precipitated by certain sulphur bacteria, making thus incrustations on the bottom of ponds or lakes. ”

“ The planets exterior to Mars—especially Jupiter and Saturn—appear spheres of water, or aqueous vapour. The Earth has a considerable atmosphere of air and of vapour; while on Venus or Mercury—so close to the sun—we see nothing of a gaseous or aqueous atmosphere; they and Mars differing little in density from the earth.
The Earth’s orbit, according to the Essayist’s theory, is the Temperate Zone of the Solar System, where only the play of hot and cold, moist and dry, is possible. Water and gases, clouds and vapours, form, mainly, the planets in the outer part of the solar system ”

“ This would have the incidental salutary effect of lowering the planetary surface temperature so that people could live unaided on the surface. However, it is not known whether biological organisms can be found or developed which are able to withstand present conditions in the Venusian atmosphere. ”

“ When we analyzed rocks at Pathfinder and Gusev, the rocks didn't contain salts. At Meridiani that was different. At Meridiani, chlorine in green is small, sulfur is in yellow. Sulfur jumped up at McKittrick before we RATted. In third bar, the sulfur jumped up (after RAT) and at Guadalupe, we have the record on Mars, almost 5 times the amount. We interpret this sulfur to be sulfate so we expect magnesium sulfate, epsom salts, on Mars with less water it's called kesorite. Kesorite plus the chlorides add up to a salt concentration that may be 40% of the outcrop. ”

“ On this same basis, it is now within the realm of science to foresee the means of predicting the development of life from primordial, nonliving chemical systems. Closely allied to the search for extraterrestrial life is research which seeks to identify the materials and the conditions which are the prerequisites of life. ”

“ What it is, only God knows. In terms of matter I suppose the thing Ammi described would be called a gas, but this gas obeyed laws that are not of our cosmos. This was no fruit of such worlds and suns as shine on the telescopes and photographic plates of our observatories. This was no breath from the skies whose motions and dimensions our astronomers measure or deem too vast to measure. It was just a colour out of space—a frightful messenger from unformed realms of infinity beyond all Nature as we know it; ”

“ CONCEPTS FOR DETECTION OF EXTRATERRESTRIAL LIFE It is not possible to present completely convincing evidence for the existence of extraterrestrial life. The problem often reduces to probabilities and to estimates of observational reliability. In almost all cases the evidence is optimistically considered strongly suggestive of—or, at the worst, not inconsistent with—the existence of extraterrestrial life. ”

“ It is no valid objection that science as yet throws no light on the far higher problem of the essence or origin of life. Who can explain what is the essence of the attraction of gravity? ”

“ No satisfactory evidence of the existence of extra-terrestrial life has, however, as yet been obtained from meteorites. The most positive and enduring results of the century's study may, therefore, perhaps be summed up as the establishment of the fact of the fall of solid cosmic matter to the earth and a sufficient knowledge of its nature to distinguish it from matter of terrestrial origin. ”

“ The carbon found in meteorites has never exhibited any trace of organic structure, and we may well imagine the carbon—e.g., that which appears to occur in the sun—to be of inorganic origin. Still more fantastic is his idea that organisms floating high in our atmosphere are caught by the attraction of meteorites flying past our planet, and are in this way carried out into universal space and deposited upon other celestial bodies. As the surface of meteorites becomes incandescent in their flight through [Pg 218] the atmosphere, any germs which they might possibly have caught would be destroyed ”

“ for I think you cannot have failed to notice that for some time hypotheses have been advanced by men of pure science which are nothing less than transcendental, and I suspect that most modern chemists and biologists of repute would not hesitate to subscribe the dictum of the old Schoolman, Omnia exeunt in mysterium, which means, I take it, that every branch of human knowledge if traced up to its source and final principles vanishes into mystery. ”