Part 7

Tektites have never been seen to fall. In spite of this fact, as we noted above, a number of scientists believe that, like the meteorites, the tektites really did come from outer space but, that they fell to earth before man was here to see them come down—or at least before he had acquired the means and skill to make lasting records of such an occurrence.

Tektites are usually quite small, weighing between 1 and 100 grams, although a few of much larger size have been found. One large specimen from the Philippines weighed about ½ pound. Two giant tektites, one weighing ¾ pound and the other over 1 pound, are in the collection of the British Museum. In composition, tektites are an impure silica-glass containing low percentages of the oxides of such elements as iron, magnesium, calcium, and titanium.

If tektite fragments are held under a lamp and observed by reflected light, their thicker parts generally appear to be jet-black. If, however, these same specimens are held up _between_ the observer and the light, then their thin razor-sharp edges are seen to be bottle-green, yellow-green, brownish, or even colorless.

In shape, many tektites are roundish or oval. Others are shaped like dumbbells, ladles, canoes, and teardrops. So they are known by those descriptive terms. One particularly interesting example is the unusual “flanged button” of Australia. Tektites of this type look like miniature South American gold-pans, the _bateas_, heaped high with pay dirt. Australian gold-field workers regarded these tektites as magical, and used them as good-luck charms. Superstitious American gold-seekers brought them into the United States all the way from Australia!

Some tektites (for example, many of the “bediasites” from Texas) are deeply grooved and channeled, and have a very jagged and irregular appearance. Even the smoother tektite surfaces are characterized by flow lines, flow ridges, and bubble pits.

Many weathered pebbles and fragments of obsidian somewhat resemble the tektites superficially. There is a very simple test by which you can distinguish true tektites from obsidian. If you hold a thin splinter of tektite glass in a blowpipe flame, the glass melts quietly but only with the greatest difficulty. On the contrary, when you test in the same flame the terrestrial glass, obsidian, it froths up much more easily, into a bubbly, whitish mass.

Although the question of where the tektites came from is still not entirely settled, most scientists agree that all tektites did have a _common_ origin. For example, tektites from widely scattered localities on the earth’s surface show not only similar queer shapes and surface markings (technically known as “sculpturing”), but also have very much the same chemical composition and, in particular, the same content of radioactive elements.

Because the tektites chemically resemble certain terrestrial rocks, scientists at first believed that some kind of earth process must have created them. One suggestion was that lightning had fused dust particles suspended in the air to form them; another, that they had come from volcanoes; still another, that the tektites were simply inclusions that had weathered out of terrestrial rocks. A few scientists once took seriously the possibility that tektites were refuse from primitive glass factories!

While such theories have not yet been completely discarded, most scientists now feel that the tektites had their origin somewhere outside the earth. There are several reasons for this belief. First, the shape of such unusually symmetrical forms as are found, for example, among the australites, indicates that these small bodies at one time were members of a swarm of freely-spinning liquid masses. Again, flow features observed on the surfaces of certain tektites (and the fusion crust definitely identified on one specimen) show that these bodies at some time must have traveled through the earth’s atmosphere at high velocity.

If, then, the tektites were not produced by earth processes, where did they come from? According to primitive legends, they were “rocks” or “pebbles” from the moon. Indeed, one of the earliest scientific theories as to their origin (proposed by the Dutch authority Verbeek in 1897) likewise attributes them to debris jetted out from the moon. Another holds that tektites are fragments of the outermost glassy layers of some so-called “meteorite-planet,” or planets.[8] Still another idea is that tektites are what is left of a comet when it passes so close to the blazing-hot sun that the “ices” which make up most of the cometary nucleus (head) are all distilled away.

These theories of the origin of the tektites are based primarily on their observed shapes, surface features, and compositions. The senior author of this book has suggested still another possible theory based on the very unusual nature of the observed distribution of the tektites on the face of the earth.

To explain this theory, we first recall that the planet on which we live is more nearly a true sphere than are such familiar “spherical” objects as baseballs or basketballs. Consequently, any plane through the center of the earth cuts its surface in a curve that to all intents and purposes is what geometers refer to as a _great circle_.

Now the significant fact is that all the tektite deposits known at present are located on or very near to three great circles on the earth’s surface. Mathematics shows that if some earth process had created the tektites at random over the surface of the earth, then the odds would be very strongly against the existence of this peculiar “great-circle distribution.” But such distribution along great circles would be _expected_ if the tektites had resulted from what might be likened to “chain-falls” upon the earth of objects like nearby satellites moving in orbits encircling our globe.

This notion brings up the interesting possibility that at some time in the remote past, the earth may have been the proud possessor of a set of equatorial rings. These rings would have been similar to those at present circling in the plane of Saturn’s equator. (Jupiter, too, may once have had its own set of equatorial rings.) The rings of Saturn are known to be made up of countless very small meteorites. In the same way, the “earth rings” of prehistory could have consisted of swarms of tiny nearby meteoritic satellites—the tektites—moving about the earth in the plane of its then-existing equator.

Eventually, the innermost of these small natural satellites collapsed onto the earth’s surface, falling along the old equator. At least twice thereafter, this process was repeated, the points of impact of the later tektite falls again lining up along whatever great circle of the earth happened to be the equator at the time of fall.

As the geologists and other investigators have shown, major shifts have occurred in the position of the earth’s equator during past geologic ages. This fact is well-substantiated by discoveries of fossil shells and plants on the cold Antarctic continent and of glacial deposits in hot South Africa. Therefore, we could hardly expect the tektite deposits, which are believed to have fallen at widely separated intervals of time, to have all occurred along a _single_ great circle on the earth’s surface.

As you can see, the so-called “tektite-puzzle” is a complex one. As if this were not bad enough, Mother Nature has added to the confusion by creating in addition to the tektites another type of silica-glass not only found along the very same three great circles sprinkled with true tektites, but also having other features in common with the tektite glasses.

At Mount Darwin in Tasmania and at Wabar in the Rub’ al Khali desert of Arabia, large and small fragments of this curious silica-glass have been collected. At Wabar the masses of silica-glass were found in and about the rims of a series of meteorite craters formed in nearly pure sand, as we pointed out in Chapter 4. These meteorite craters are known to have resulted from the high-speed impact of iron meteorites upon the sand dunes of the Wabar site. Since the silica-glasses of Wabar have been found to contain countless spherules of nickel-iron of the same composition as the iron meteorites discovered about the Wabar meteorite craters, it seems quite certain that both the sand of the earth target and the nickel-iron of the falling meteorites were vaporized by the intense heat generated at impact. Consequently, it is natural that these Wabar masses of congealed silica-glass and nickel-iron be called _impactites_. They are silica-glasses, created chiefly from _terrestrial_ materials by the impact of large crater-forming meteorites. This same name is now applied to all silica-glasses believed to have the same origin as those at Wabar.

As regards size if not composition, the crater-forming meteorites responsible for the Wabar and other impactites may have been big brothers of the small-fry responsible for the showers of true tektites. Or these big ones may have moved about the earth in orbits distinct from those followed by the tektite swarms but lying in the same plane as one of these swarms.

In addition to the curious puzzle of the tektites, meteoriticists have also run up against the problem of “fossil” meteorites or, more exactly, the problem of the _lack_ of “fossil” meteorites. As we have already mentioned, no positively identified meteorite has ever been found in other than the most recent rock layers. With all the mining—particularly coal mining—that has gone on throughout the world in historic times, this fact does seem astonishing.

A number of explanations can be suggested for this absence of ancient meteorites. In the geologic past, meteorite falls may not have occurred as often as they do today. For example, the primeval atmosphere of the earth may have been so much denser than at present that even quite large meteorites were totally vaporized as they passed through it and therefore never reached the ground. Again, even if the rate of infall of meteorites was the same in the remote past as now, still various weathering processes active ever since the earliest meteorites fell may have so changed them in appearance and composition that they are no longer recognizable for what they are.

Several unusual lumps of rock from England and a mass of iron from Austria, all found at some depth by coal miners, have been tentatively put forward as “fossil” meteorites. But studies of these masses have so far produced no conclusive results. Still, we should not ignore the possibility that someday meteorites may be found and identified in rocks of considerable age.

Does it seem as if we have posed more problems than we have solved in this chapter? It is very true that we have done just that. In speaking briefly about the tektites, the impactites, and the absence of “fossil” meteorites, we have by no means tried to present the last word on the troublesome but highly interesting problems connected with these objects—problems that admittedly may take scientists years or even decades of further research to solve. Perhaps you will find here the kind of unusual and thought-provoking problems that make the study of meteorites a rather special challenge. If so, you may wish to take an active part someday in unraveling these puzzles.

11. OMENS AND FANTASIES

Men seem to have always taken an interest in meteorites, but not until the early nineteenth century were these objects considered to be worth preserving for _scientific_ study.

In the beginning, people believed that because meteorites fell from the heavens, they were either gods themselves or messengers from the gods. The more civilized of early men therefore carefully kept the fallen meteorites. They draped them in costly linens and anointed them with oil. In many instances, the people built special temples in which meteorites were actually worshipped. Some of the holy stones of the ancients, such as the Diana of the Ephesians, mentioned in the Bible as “the image which fell down from Jupiter,”[9] are now thought to have been meteorites.

Meteorite worship was common long ago in the Mediterranean area and in Africa, India, Japan, and Mexico. This practice still persists in some regions even in modern times. The Black Stone of the Kaaba, for example, has been sacred to all Mohammedans from about 700 A.D. right up to the present. It is said to be a meteorite although this fact has never been verified, because strict religious taboos connected with the stone prevent any scientific examination or study of it. On the contrary, the Andhâra, India, meteorite is known to be a genuine one. The story of the fall and preservation of this meteorite provides a fairly modern example of practices rooted in the ritual and custom of far more ancient times.

At about 4:00 in the afternoon of December 2, 1880, the people of Andhâra heard a noise like that made by a gun. Some of the villagers saw a “dark ball” come to earth in a field near them. This falling object sent up a small cloud of dust as it struck the ground. After the stone had been recovered from the field and the dust had been washed from its surface, two Brahmin priests took charge of it and began to collect money for the erection of a temple in which the holy object could be properly displayed.

The scientist who promptly investigated the Andhâra fall reported that throngs of worshippers were crowding into the as yet unfinished brick temple to make offerings of flowers, sweetmeats, milk, rice, water, bel leaves, and of course money. The stone had been named Adbhuta-Nâth, “the miraculous god.” It was shaped like a round loaf of blackish bread and weighed an estimated 6 pounds. The scientist was not allowed to touch it, but he got close enough to verify that the stone was a meteorite covered with a typical blackish fusion crust.

Not only has man worshipped meteorites, but during a period extending from approximately 300 B.C. to 300 A.D., emperors and self-governing cities frequently marked the fall of meteorites by minting special coins or medals known as _betyls_.[10] One of these is the betyl of Emisa, Syria, made by Antonius Pius (138-161 A.D.). The historian, Herodotus, accurately described the object honored by this betyl as: “A large stone, which on the lower side is round, and above runs gradually to a point. It has nearly the form of a cone, and is of a black color. _People say of it in earnest that it fell from Heaven._” The stone is shown on the coin as carried on a quadriga (a carriage drawn by four horses) under a canopy of four sunshades.

Many ancient peoples held meteorites in great reverence, particularly if they were seen to fall. But at the same time, other more practical-minded individuals made good use of the durable and easily worked alloy provided by nature in the nickel-iron meteorites. This alloy was frequently used to make ax-heads, spear and harpoon points, knives, farming tools, stirrups and spurs, and even pots and other utensils. Archeologists have found earrings and similar ornaments overlaid with thin sheets of hammered meteoritic iron in Indian mounds of the Ohio Valley. They have also discovered round beads made of nickel-iron in Indian mounds of the Havana, Illinois, area and in the still more ancient Egyptian ruins at Gerzah.

Meteoritic iron has often been used in the manufacture of special swords, daggers, and knives for members of the royalty. Atilla and other early conquerors of Europe boasted of “swords from heaven.” Emperor Jehangir (1605-1627) ordered two sword blades, a knife, and a dagger to be smelted from the Jalandhar, India, meteorite, which fell on April 10, 1621. In the early nineteenth century, a sword was manufactured from a portion of the Cape of Good Hope meteorite for presentation to Alexander, the Emperor of Russia. Even as late as the end of the nineteenth century, several swords were made from a part of the Shirihagi, Japan, iron meteorite at the command of a member of the Japanese court.

In the Europe of the Middle Ages, meteorite falls and meteor showers, as well as other “unnatural” events like comets, eclipses, and displays of the aurora borealis, were regarded with superstitious awe by commoner and king alike. The medieval mind always sought to interpret events connected in any way with the heavens as somehow influencing the affairs of men. A bishop explained that the great meteor shower of April 4, 1095, forecast “the changes and wanderings of nations from kingdom to kingdom.” The fact, however, that the First Crusade began within a year, is mere coincidence.

In referring to celestial events, Shakespeare often expressed the view that was common in the Middle Ages and the Renaissance. An example is:

The bay-trees in our country are all wither’d And meteors fright the fixed stars of heaven; The pale-faced moon looks bloody on the earth And lean-look’d prophets whisper fearful change, . . . . . . These signs forerun the death or fall of kings. (_Richard II_, II, iv, 8-11, 15)

Yet the descent of meteorites from the heavens was not always regarded as a forewarning of bad fortune. On November 16, 1492, a 279-pound meteorite fell at Ensisheim in Alsace, not far from the battle line separating the armies of France and the Holy Roman Empire. Emperor Maximilian, the leader of the Empire’s forces, commanded that the fallen stone be carried to his castle. There a formal war-council was held to determine what the strange event could mean.

The Emperor and his councillors decided that the fall of the meteorite at such a time and place was an omen of divine favor which meant good fortune to the cause of the Holy Roman Empire. After breaking off two small pieces of the stone, one for the Duke of Austria and one for himself, the Emperor forbade further damage to it. He also gave orders that the stone be hung in the parish church in Ensisheim for all to see. In this way, the Ensisheim stone became the very first meteorite of witnessed fall to be preserved down to the present day—and all because of the superstition of a famous military leader.

The discussion to this point makes clear that in ancient, medieval, and Renaissance times, meteorite falls were considered as startling and disturbing events, which frequently were interpreted in strange and mistaken ways. But the fact that meteorites actually did fall from the heavens was not questioned. As the so-called “Age of Reason” opened, a curious change in attitude toward meteorite falls took place.

At the very time that knowledge in general increased, men of learning began to deny that meteorite falls occurred at all! The scientists of the French Academy, in particular, were very positive on this point. Since the era was one in which all Europe sneezed if “la belle France” had a cold in the head, it was a trying time not only for the early meteoriticists, but for all who had the nerve to insist they had seen rocks fall from the sky.

By the end of the 1700’s, the authorities had studied the evidence relating to meteorite falls and had completely rejected it. They said that there was no “proof” whatever that “stones fell from the heavens.” These early scientists openly sneered at people who claimed that they had seen meteorites fall. It was felt that the spectators of such events either had merely been “seeing things,” or had surely been reporting light and sound effects connected with nothing but ordinary thunderstorms.

When confronted with the “fallen” masses themselves, the authorities often refused to examine them, or if they did, insisted that these masses were only rocks that had been struck by lightning. Such were the opinions of learned men around the close of the eighteenth century.

Fortunately, scientific facts have a stubborn way of winning out in the long run. A major part of the credit for seeing that the truth regarding meteorite falls was at last recognized must go to E. F. F. Chladni, a German physicist, and to Edward Howard, an English chemist.

In 1794, Chladni published an extremely important paper concerning a large spongelike mass of “native iron” found near Krasnoyarsk, Russia. This object had been discovered in 1749 by a Russian blacksmith, and it was studied in 1772 by P. S. Pallas, an early traveler. Chladni concluded that the mass of iron[11] must have fallen from the heavens, because it had been “fused” (but not by man, electricity, or fire) and also because there were no volcanoes anywhere around its place of find.

Chladni supported his theory by listing numerous reports of meteorite falls dating from ancient and medieval times. But Chladni’s fellow scientists flatly rejected his theory as clever but not satisfactory.

With the fall of the Siena meteorites in Italy on June 16, 1794, the controversy regarding the possibility that stones actually fell from the sky became particularly heated, and remained so for nearly ten years. During this interval, two other important meteorite falls occurred: Wold Cottage, England, on December 13, 1795, and Benares, India, on December 19, 1798. Scientists had a hard time finding explanations for these well-observed events, and some of the theories put forward to account for them far outdid Chladni’s in “cleverness,” if that be the correct word.

One scholar, writing in 1796, suggested that the masses which fell at Siena resulted from the solidification at great height of volcanic ashes from Mount Vesuvius. These ashes had supposedly been carried northward beyond Siena and then been “brought back by a northerly wind, congealing from the air....”

Fortunately, in 1803 Edward Howard’s chemical work on meteorites came to a successful conclusion. This patient chemist made analyses of samples from the Siena, Wold Cottage, and Benares falls and from an older Bohemian fall. He also had the samples studied mineralogically by a fellow scientist. From the results of these investigations, he drew the following conclusions, which admirably supported Chladni’s well-reasoned and thoroughly documented theory regarding meteorite falls:

All four of the stones studied had very nearly the same composition.

Despite the fact that the stones contained no new elements, their mineralogical character differed in several important respects from that of any rocks found naturally on the earth.

The four masses must have had a common origin although their reported falls had been widely separated both in time and in space.

Finally, said Howard, it was quite possible that the stones had really fallen from the sky.