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| Most meteorites are made of iron, right? |
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Well, yes and no. You see, most meteorites observed to fall are of the
stone type. Observed falls of iron meteorites occur only about 4% of the
time. However most meteorites that are found are irons because terrestrial
weathering breaks down stones more rapidly than irons. In other words, stone
meteorites do not survive as long on the Earth's surface as iron meteorites
do (although weathering also eventually affects irons as
well). |
| When they land on the Earth, meteorites always
glow with heat from their passage through the Earth's atmosphere. |
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Actually, no. Although there is some controversy as to whether or not
some meteorites are warm to the touch when they fall, most meteorites are
cool when they land on the Earth's surface. They travel so fast through the
Earth's atmosphere, the heat produced during entry is ablated away, much
the same way that the tiles on the underside of the space shuttle (and heat
shields on prior space capsules) protect the shuttle. In fact, the aerodynamic
shape of oriented meteorites was the inspiration for the blunt heat shield
design of the Mercury/Gemini/Apollo space capsules. |
| Meteorites have been known to carry diseases
from space which can harm anyone who comes into contact with one. |
| Meteorites
do not inherently carry diseases from space. There has never been any
sign of any living bacteria or virus associated with or naturally occuring
within a meteorite. Such germs, as well as spores molds and fungus
may attach to a meteorite after it lands, but that is part of the
terrestrialization process. |
| Meteorites have been in space for a long time,
therefore they are are radioactive, right? |
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No, meteorites are not radioactive.
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