Meteors and Meteorites
The study of meteors dates back only about a century
and a half. Early man must have wondered about the meteors when
they flashed across the sky on a clear night. The ancient Greeks
named them “Meteor”, which meant “things in
the air” and included clouds, whirlwinds and lightning.
It is not known definitely where meteors come from, but many scientists believe
there may once have been a planet between Mars and Jupiter in our solar system,
and that it exploded long ago. Hundreds of asteroids have been identified in
that approximate orbit that may have been part of its debris.
Meteors are pieces of matter, which fall from outer space. When they enter the
earth’s atmosphere, they move very swiftly and are sometimes called “shooting
stars”. The air friction heats the meteors to about 4000 degrees Fahrenheit
and they usually burn up high in the atmosphere.
Meteors, which reach the earth, are called meteorites. Sometimes they burst into
many fragments when they strike the atmosphere. The Meteor Crater near Winslow,
Arizona was made some 20,000 years ago when a huge cluster of meteorites struck
from the Northern sky. It is believed to have weighed at least a million tons.
The crater is nearly a mile wide and 570 feet deep. Thousands of meteorites have
been found around it, and in nearby Diablo Canyon, meteorites containing diamonds
have been discovered.
Meteorites are generally classified into three groups: Iron, Stonyiron and Stony.
Over 90% of the meteorites that fall are stony, but individuals are more likely
to find iron meteorite specimens. Most stony meteorites are made up of the same
minerals that make up ordinary volcanic rocks, but these can also contain small
pieces of nickel-iron called chondrules. When an iron meteorite is cut, polished
and etched with acid, an interesting pattern often appears.
The largest nickel-iron meteorite found in this country in this century is on
display at the Douglas County Historical Society Museum at Waterville, Washington.
The meteorite fell in 1917 on a farm north of Waterville and weighs 82 ½ pounds.
Other meteorites found in the same area are also on exhibit there.
Meteorites and lunar rocks are the only extra-terrestrial matter available to
us to study. Since there are no samples of the material from the interior of
the earth, meteorites give us some idea of the type of material that may be found
there.