Marco Langbroek wrote regarding the object found in Southend, England in November 1968: > The object on the photo looks like pieces of industrial slag I have seen. So > that would be my first interpretation of it, rather than space debris, unless > something in the composition/morphology suggests otherwise and clearly connects > it to space debris. > > Note that each year I get several reports (as potential "meteorites") of objects > that did damage, including objects that went through windows. Invariably it is > accompanied by "reasons" (as in the BAA article) why it/the damage "cannot" have > a terrestrial origin. Over the past 20 years none of it however was a genuine > meteorite or space debris. So be careful there. Thank you, Marco. In my notes from Pierre Neirinck, I have the results of a chemical analysis of the stone attributed to A.J. Christopher: CaO 40% MgO 18% SiO2 38% Al2O3 9% Mn,Ba,Fe,B,<1% This does seem like slag from iron or steelmaking. http://www.nationalslag.org/sites/nationalslag/files/documents/nsa_182-6_properties_and_uses_slag.pdf Table 1 Major Chemical Constituents in Blast Furnace Slag Constituent Weight Percent Lime (CaO) 32 to 45 Magnesia (MgO) 5 to 15 Silica (Si02) 32 to 42 Alumina(Al203) 7 to 16 Sulfur (S) 1 to 2 Iron Oxide (Fe203) 0.1 to 1.5 Manganese Oxide (MnO) 0.2 to 1.0 The B.A.A. paper I quoted from had the results of a different type of test: "The rock is a ceramic, bluish grey in colour and very hard, and from an X-ray fluorescence analysis, the following composition was obtained: iron 100 parts, barium 75 parts, strontium 30 parts, manganese 20 parts, zinc 10 parts, copper 5 parts, yttrium 5 parts. The above accounts for less than 5 % of the whole sample." I do not know which test to believe. Would a material with either set of properties have been a likely component of a rocket stage, or likely to have formed during re-entry? 1968-102B / 3543, was a Russian model 11A57I stage. Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Wed Dec 31 2014 - 08:49:03 UTC
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