#96 June 1996
Section 126.96.36.199.096.of the Artemis Data Book
Peter KokhABORIGINAL AND STILL ONGOING LUNAR PRODUCTION OF GLASS FROM MOONDUST
Our terrestrial economy owes a great debt to the natural production of sand and gravel, marble, granite, slate, and veins of concentrated metal ores. These handy prepared materials have been naturally produced through the eons by geological processes. And of course, where would we be without those biologically assisted geological processes that have resulted in the natural production, and warehousing, of limestone, chalk, coal, oil, gas, shale, and other fossil derivatives? "Natural Production" - if you will not admit "Natural Manufacturing" - has given our species an enormous handicap, without which, for all our pretentious brainpower, we might still be in the caves or in the forests.
Our outpost construction efforts, at least long term, stand to gain from the natural production of craters, rilles, and lavatubes. When it comes to future production of building materials and processing in general, while the chemical and mineral assets of the Moon would seem very homogenized in comparison to those of Earth, there has been some helpful beneficiation and enrichment. Highland soils are richer in aluminum, magnesium, and calcium. Mare soils are richer in iron and titanium. The splashout from the Mare Imbrium impact event is enriched in the so-called KREEP deposits: potassium, rare earth elements, and phosphorous.
More, we suspect the as yet unsampled central peaks of large craters represent upthrusts of deep mantle material; and that may prove a useful starting point in the production of some useful chemical elements. Finally, we have hope that some of the crater impacts were caused by asteroids rich in elements otherwise scarce on the Moon - like that which caused the Sudbury, Ontario astrobleme, source of much of the world's nickel and copper.
1.01 One of the special handy features of the regolith is the presence of a considerable amount of pure "iron fines", unoxidized (non-rusted) iron particles. Some years ago, Seattle LUnar Group Studies (SLUGS) determined that if you excavate a site (for the placement of a soil-shielded habitat), you will find in the material removed, enough pure iron particles from which to build the habitat to be placed in the excavation. This resource can be recovered for the price of a simple magnet. [MMM # 63 MAR '93 "Sintered Iron from Powder"].
1.02 Another special enhanced feature of the regolith is a considerable bounty of adsorbed solar wind gases [MMM # 23 MAR '89 pp 4-5 "Gas Scavenging"; MMM # 38 SEP '90 p 4 "Introductory Concepts of Regolith Primage"], thanks to eons of buffeting of the surface by the Solar Wind, blowing outward from the Sun's surface. Involved are considerable amounts of hydrogen, nitrogen, carbon, garden variety helium, helium-3, neon, argon, and krypton, all recoverable through the application of a little concentrated solar heat.
1.03 Nor is that all. A third natural production within the regolith has been going on - again for billions of years. The natural production of glass spherules from the heat of micro-meteorite impacts.
Impact-derived lunar glasses are commonly found as spheres, the rotational shapes assumed by splashed liquids, ranging widely in size. 100 microns [m] in diameter is typical (i.e. about a hundredth of a centimeter or 4 thousandths of an inch). [p. 128] Interestingly enough, this size/shape range are what we find on Earth for algal and bacterial one-celled micro-fossils, though the composition is totally different [p. 134].
The spherules are often flattened owing to the degree of plasticity at the time they "landed". Broken pieces are common as are irregular masses coating larger particles in blotches. The spherules are themselves commonly "cratered" by even smaller micrometeorite impacts than those that led to their formation. Colors range from colorless through pale yellow, green, brown, orange to red, and black, and show a clear relation to refractive index and to chemical composition of the regolith material that became glassified by heat [p. 128].
Some glass spheres have inclusions of iron and nickel of foreign (meteorite) origin. Overall, the glasses are identical in composition to the host regolith material from which they were transformed [pp. 129-133].
These glass spherules are found in all lunar regolith soils, though the percentage by weight and volume varies.
Glass spherules, given their uncontrolled composition and color, still offer a number of useful product possibilities and applications that will give the early outpost/settlement-to-be an economically significant leg up. Here are some:
The list of capital equipment needed is modest:
As goals of lunar industry and export development, these product lines may seem minor. But together with the use of sintered iron products and regolith scavenged gases, they will work to jump start early and easy industrial diversification, cutting a small but significant part of the import burden, and giving the pioneers a well-deserved sense of achievement.
[EDITOR: INCLUDE THE following paragraph only if you are able to scan in the mentioned logo from the hardcopy]
The Made-on-Luna logo will have humble application at first, but thanks to prior "natural production" and serendipitously provident stock-piling of "not-quite-from-scratch materials", Lunar pioneers will be the beneficiaries of an industrial and economic handicap analogous, if not similar, to those we have enjoyed here on the cradle world. MMM
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