Chapter V: Preface: 5 (4)

In 1955, however, scientists at Purdue University, using more refined counters, studied small nuggets of nickel-iron, also from the Norton meteorite. This time, the results of the radioactivity tests were positive. The investigators detected tritium (an isotope of hydrogen produced by cosmic-ray bombardment) in the samples. Furthermore, the _amount_ of this rare isotope present indicated that the intensity of cosmic radiation outside the earth’s atmosphere may be very much higher than had previously been thought possible. “Forewarned is forearmed,” and from the standpoint of future astronauts, this is as practical a result as one could wish for!

In the relatively near future, men will certainly land on the surface of the moon. We know from radiometric studies that some degree of radioactivity is induced in meteorites by the full-intensity cosmic radiation to which they have been exposed during their motion through space. The nearly airless moon, like the meteorites, has also been exposed to very intense cosmic radiation for a long time. So those who are planning to land on our satellite are concerned about the radioactivities they will encounter when they begin their explorations of the lunar surface.

Suppose that extra-sensitive instruments were designed to pick up and measure the radioactivities. Suppose further that these instruments were mounted in a space-probe put in an orbit circling closely about the moon. Plans for such a project are now under way. What types and intensities of lunar radioactivities might such probe-mounted instruments record?

Until such a space-probe becomes available, earth-bound space-scientists are seeking at least a preliminary answer to this question. They are doing this by investigating the natural “probes” that have come to us from space—the meteorites.

Investigators have undertaken such studies very recently by employing a new radiometric method technically called _gamma-ray spectroscopy_. Work of this sort has been and is being done at the Los Alamos, New Mexico, Scientific Laboratory on scores of meteorite and tektite specimens loaned to the Laboratory by the Institute of Meteoritics. Some of the individual meteorite specimens tested weighed as much as 37 pounds, and are probably the largest single extra-terrestrial masses yet tested for cosmic ray-induced radioactivities.

Let us turn now to another important application of meteoritics. Any body in motion through the air or in space has a “striking power” of sorts. For some objects, this striking power, which is technically known as _ballistic potential_, is very weak, as in the case of silky milkweed-down drifting through the air. Hailstones have a good deal more striking power, as may have been painfully demonstrated on your own head. And, finally, such masses as falling meteorites (and especially those orbiting in space, unretarded by atmospheric resistance) have an extraordinarily formidable ballistic potential. This is because meteorites are not only tough and dense, as good projectiles must be, but are also moving at high velocities—particularly high if the meteorites come into the Solar System from interstellar space.

For this reason, the speeds of meteorites are very important to scientists responsible for rocket flights and for keeping satellites aloft over long periods of time. Clearly, these men must have as accurate information as possible on where and how fast meteoritic particles are moving, so as to chart the safest routes for spaceships, and to develop satisfactory means of protecting rockets and satellites against the effects of bombardment by the smaller meteorites. For these “small-fry” cosmic missiles are so numerous that many of them are sure to be encountered even in brief flights outside the earth’s atmosphere.

Such information might also prove valuable in the future to the crews of spaceships on long flights into deep space. Such men may face the life or death problem of taking successful “evasive action” against giant meteorites that will seem like flying hills and mountains.

A strong parallelism exists between a meteorite fall and the re-entry of a nose-cone or data-capsule into the atmosphere. To a considerable extent, the difficult problems connected with the latter are being attacked at present through careful studies of meteorites. From the air-sculptured shapes of meteorites, their crustal flow patterns, and the thicknesses and types of fusion crusts they show, scientists are learning a great deal about certain factors connected with the re-entry problem. These factors include rate of vaporization, effects of extreme temperatures, and types of sculpturing to be expected as a result of encountering the resisting molecules of the atmosphere.

A. A METEORITE FALL
B. A V-2 RE-ENTRY]

One of the most obvious applications of meteoritics in the future will grow out of the well-known fact that our earthly resources of many strategic materials—especially metals like iron and nickel—are fast becoming exhausted. The population of the earth is increasing at a mad pace, and an end to metal-consuming wars is still not in sight. The need for such metals can only become more and more acute.

According to one of the currently favored explanations of the origin of the meteorites, the core-fragments of the parent meteorite-planet are solid masses of nickel-iron alloy—like the mass that blasted out the Canyon Diablo meteorite crater. If this meteorite-planet hypothesis finally wins general acceptance, the meteoriticist of the future is almost sure to be set the task of pin-pointing as exactly as possible the whereabouts in space and time of the most easily accessible cosmic nickel-iron lodes of this sort. Once he has given an answer, the space engineers will take over, and mining operations will be started on the unlimited sources of essential metals to be found in outer space.

Initially, no doubt, metal recoveries will be freighted back to earth in rocket-load lots. But as the need for iron and nickel increases on a metal-hungry earth, vast engineering projects may well be undertaken to “snare” the larger metal meteorites and equip them with rocket motors. This will be done so that by use of rocket power, the natural orbits of the meteorites can be changed into orbits bringing them back to earth. Unlike the natural, uncontrolled Canyon Diablo meteorite fall that vaporized what would have been a rich nickel-iron deposit, the rocket-controlled meteoritic “metal mines” will be eased down to earth all in one piece.

Reading of the possibility of sending out expeditions to find large iron meteorites in the depths of space may bring to your mind an image of the fearless mariners of old who sailed their stout ships over dangerous, often uncharted seas in search of the great whales. The rocket crews of day-after-tomorrow will no doubt be equally fearless and resourceful as they navigate the sea of space, intent on capturing the great “metal mines” of the future.

The experience gained in such space-mining ventures will then be carried over into expeditions to ensnare the larger stony-iron meteorites. These masses of iron and stone will offer less favorable mining possibilities, but they can be turned into rocket-propelled and guided de luxe space-cruisers. By this term, we do not mean that these natural space-ships will house all the luxuries of the ocean-liners advertised in the travel magazines. Rather, we see them as providing roomy, comfortable “underground” living quarters. Furthermore, their occupants will be adequately protected by great thicknesses of metal and rock from the injurious radiations of empty space, and the meteorites that make the term “empty space” something of a misnomer.

Initially, such worlds-in-miniature will be much sought after as laboratory sites where the more violent and dangerous of the many experimental tests which venturesome man will wish to conduct can be carried on without danger to the close-packed billions populating the then-crowded earth.

Later on, these meteorites-turned-into-space-ships may be used to explore the dangerous and faraway corners of the Solar System, since the very substance of each massive meteoritic rocket-body will serve as an adequate and handy source of fuel supply.

When men have learned to live on such “homes away from home,” it is quite possible that the larger of these modified meteorites, after their interiors have been opened up for occupancy by the inroads of the fuel-hungry rocket-motors, may be steered into neighborly orbits about old Mother Earth. Here, these “natural” satellites will assume the unexciting but necessary roles of the extra living quarters that by then will be so urgently needed to accommodate the mushrooming population of the world of the future.

People who live in these super-urban outliers of Mother Earth may take the same pride in their natural, if converted, homes as many former city dwellers now take in the old-fashioned sprawling farmhouses they have rebuilt and occupied. Perhaps one of your descendants will live in such a meteorite-orb, and occasionally point the finger of scorn at the more elegant but unpleasantly overcrowded artificial satellites preferred by those migrants from teeming earth who lack the true pioneering instinct. Who knows!

FOR FURTHER READING

If you are especially interested in meteoritics, you already may have read some good books on general astronomy. There are many and most of them are not too advanced for the beginner. Unfortunately, these books devote but little space to meteoritics, the “Johnny-come-lately” of astronomy. Almost all of the writings on meteors and meteorites you will find largely profitable to read are in professional meteoritical publications. A selected list of such publications, containing much or at least a worthwhile amount of material you will now be able to understand, is given below. Your chief difficulty in using this list will be in finding some of the more important items in the holdings of your public library, unless it is a large and well-stocked one. Your librarian, however, may be able to help you get the item from some other library—perhaps from that of a nearby university or college.

METEORIC ASTRONOMY

MEBANE, A. D. “The Canadian Fireball Procession of 1913, February 9,” _Meteoritics_, Vol. 1, No. 4 (1956), pp. 405-421. Eyewitness accounts of the most famous fireball procession on record.

OLIVIER, C. P. _Meteors_, Williams and Wilkins, Baltimore, 1925. An exhaustive survey of work done by visual meteor-observers.

SCHIAPARELLI, G. V. _Shooting Stars_, a translation by C. C. Wylie and J. R. Naiden, published in the _Proceedings, Iowa Academy of Science_, Vol. 50 (1943), pp. 48-153. A pioneer treatise, dated 1867, which is basic to later work in this field.

WHIPPLE, F. L. “Photographic Meteor Studies, I,” _Proceedings, American Philosophical Society_, Vol. 79, No. 4 (1938), pp. 499-548. Fundamental paper on the subject. Of the six meteors analyzed, five followed elliptical orbits and one, a strongly hyperbolic orbit.

METEORITES

FARRINGTON, O. C. “A Catalogue of the Meteorites of North America to January 1, 1909,” _Memoirs, National Academy of Sciences_, Vol. 13 (1915). Contains fascinating accounts of the phenomena connected with meteorite falls, interspersed with lengthy technical chemical and microscopic studies of meteorites.

FARRINGTON, O. C. _Meteorites_ [published by the author], Chicago, 1915. The classic American work on meteorites. The first half of the book is popular; the last half is technical.

HEY, M. H. and PRIOR, G. T. _Catalogue of Meteorites_, William Clowes & Sons, London, 1953. An exhaustive catalog of all recognized and also, unfortunately, of many doubtful meteorite falls and finds, from the beginning of the historical record up to December 1952.

LAPAZ, LINCOLN. “The Achondritic Shower of February 18, 1948,” _Publications, Astronomical Society of the Pacific_, Vol. 61 (1949), pp. 63-73.

LAPAZ, LINCOLN. “The Effects of Meteorites upon the Earth,” _Advances in Geophysics_, Vol. 4, edited by H. E. Landsberg, Academic Press, New York, 1958, pp. 217-350. A monograph covering such topics as meteorite hits upon buildings and people, meteorite detectors, and the nature and age of meteorite craters.

LEONARD, F. C. “The Furnas County, Kansas, Achondritic Fall (1000,400),” _Contributions, Meteoritical Society_, Vol. 4 (1948), pp. 138-141. This paper and the eighth item, above, discuss the phenomena of the fall of the largest aerolite so far recovered anywhere in the world.

MERRILL, G. P. “The Story of Meteorites,” _Minerals from Earth and Sky_, Vol. 3, Part I, Smithsonian Scientific Series, 1929, pp. 1-163. A chiefly popular survey of the subject by a master meteoriticist.

PERRY, S. H. _The Metallography of Meteoric_ [meteoritic] _Iron_, U. S. National Museum Bulletin No. 184 (1944). A summary of knowledge on the subject, supplemented by exceptionally fine photographs of etched meteorite sections.

SWINDEL, G. W., JR., and JONES, WALTER B. “The Sylacauga, Talladega County, Alabama, Aerolite: A Recent Meteoritic Fall that Injured a Human Being,” _Meteoritics_, Vol. 1, No. 2 (1954), pp. 125-132.

WHITE, C. S. and BENSON, OTIS O. (editors) _Physics and Medicine of the Upper Atmosphere_, University of New Mexico Press, Albuquerque, 1952. See Chapter X, “Meteoritic Phenomena and Meteorites,” by F. L. Whipple, pp. 137-170; and Chapter XIX, “Meteoroids, Meteorites, and Hyperbolic Meteoritic Velocities,” by Lincoln LaPaz, pp. 352-393. Modern views on the meteorite velocity controversy.

METEORITE CRATERS

LAPAZ, LINCOLN. “The Craters on the Moon,” _Scientific American_, Vol. 181, No. 4 (1949), pp. 2-3. A popular exposition of the Bénard-Wasiutynski theory of the origin of the ordinary (nonrayed) craters on the moon.

SPENCER, L. J. “Meteorite Craters as Topographical Features on the Earth’s Surface,” _Geographical Journal_, Vol. 81 (1933), pp. 227-248. The classic paper on terrestrial meteorite craters.

METEORITIC DUST

BUDDHUE, J. D. _Meteoritic Dust_, The University of New Mexico Press, Albuquerque, 1950. An account of the various techniques used in collecting and studying meteoritic dust; and also of the conclusions drawn from the study of such dust.

INDEX

A
achondrites, 126, 163, 178
Adelie Land stone, 78
Adrar iron, 38, 40
aerolites, 178, 179
_see also_, stones, meteoritic
age of meteorites and/or craters, 50, 52
Aggie Creek iron, 76
Ahnighito iron, 36, 128
Algoma meteorite, 75
“Alley Oop’s shillelagh,” 126
altitude, 88, 90, 105, 106
American Meteor Society, 116
American Museum of Natural History, 37
Anderson Township meteorites, 76
Andhâra stone, 147-8
Andromeda, Great Spiral Nebula in, 2
Andromedid shower, 153
anthills, meteorites in, 128
anti-matter, 58-60
Aouelloul crater, 65
appearance and disappearance of meteors, 86, 94, 106
applied science, 166
archeologists, 76, 150
areas of fall, 13-4, 24, 26, 32, 89, 94, 159
armor plate, 167
asteroid belt and orbits, 160-1
astronautics, 110, 168, 170-6
ataxites, 120
Athens, multiple fireball over, 149
australites, 134, 140
azimuth, astronomical, 88

B
Bacubirito iron, 128
Bald Eagle iron, 76
ballistic potential, 171
Baxter stone, 73
Bear Lodge iron, 76
Beddgelert stone, 69-70, 73, 168
bediasites, 136, 137
Belly River stone, 131
Benares meteorite, 156
Bendego iron, 128
Benld stone, 73
Benson, O. O., 179
Bethlehem stone, 73
betyls, 148, 150
Bible, meteorite mentioned in, 147
Bielid shower, 116
“blackfellows’ buttons,” 134
Black Stone of the Kaaba, 147
Boisse, A., 160, 163
bolides, 102, 151
Braunau iron, 73
Brenham craters and meteorites, 52, 65, 66, 78
Box Hole Station crater, 65
Bridgewater meteorite, 75
British Museum, 136, 158
Buddhue, J. D., 179