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Today, we can hardly believe that meteorites did not attract much serious scientific
attention during the early centuries of the Enlightenment. When they did, they were usually explained
by atmospheric processes, similar to showers of hail condensing in clouds, or as terrestrial rocks
that had been struck by lightning - hence the name "thunderstones". Others believed that
meteorites were volcanic rocks, violently spewed out during major eruptions. Noone even considered
the possibility that meteorites might be genuine rocks from space. |
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The Pallas Iron and Ernst F. Chladni
Until the early 19th century, most scientists shared Isaac Newton's view that no small objects
could exist in the interplanetary space - an assumption leaving no room for stones falling from
the sky. However, a major shift in paradigms was on its way in the last decades of the 18th century,
and it started off with a rather unusual find.
In late 1772, during one of his travels through the remote areas of Siberia on behalf of czarina
Catharina the Great, the German naturalist Peter Pallas examined a huge iron mass near the town of
Krasnojarsk - a mass of which the Tartars said that it had fallen from the sky. The 700kg iron
caught the scientist's attention - it was partly covered with a black crust, and there were lots of
translucent olivine crystals (peridots) set in its iron matrix, something Pallas had never seen,
nor heard about before. Unwittingly, he had discovered a brand-new type of meteorite, a class of
stony-iron meteorites that would later be named for him: the pallasites.
Pallas' subsequent report encouraged a German physicist, Ernst Florens Chladni, to publish his
audacious thesis that this and other finds actually represent genuine rocks from space. In his
booklet, "On the Origin of the Pallas Iron and Other Similar to it, and on Some Associated
Natural Phenomena", published in 1794, he gathered all available data on meteorite finds and
falls, forcing him to the conclusion that meteorites actually are responsible for the phenomena
known as fireballs, and - yet more important - that they must have their origin in outer space.
Chladni's view received immediate resitance and mockery by the scientific community. In the late 1790s,
rocks from space just didn't fit into the concept of nature. However, it was nature itself that
came to Chladni's aid in the form of two witnessed meteorite falls, making him the father of a
new discipline - the science of meteoritics.
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Ernst Florens Friedrich Chladni
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