An actual meteorite
A meteorite is a rock or metal fragments of sufficient size to
reach the earth’s surface without burning up completely in the
atmosphere. Actually it is a relatively small fragment of debris in the
solar system. On entering a planets atmosphere, the meteorite heats up and
partially or completely vaporize; leaving a trail of glowing vapor and
those that survives to reach the ground is known as meteorite.
Despite some fearful story circulating around, most meteors
disintegrate when entering the earth’s atmosphere, making impact events
on the surface uncommon. However large meteorites may strike the earth
with considerable force leaving a huge crater. This would certainly cause
widespread havoc and the impact will in fact be very catastrophic. The
great impact referred to as the K-T Event where about 70% of all species
disappeared some sixty five million years is believed to have been caused
by a meteorite. Such is the impact of the meteorite disaster; this event
is suggested to have caused the extinction of the dinosaurs and also
resulted in a dramatic change in the climate.
The average speed of
meteoroids entering our atmosphere is 10-70 km/second. But it’s
fortunate that those that mostly enter the earth's surface are small ones,
which are quickly slowed by atmospheric friction to speeds of a few
hundred kilometers per hour, thus the impact is not that strong. For
meteorites larger than a few hundred tons, atmospheric friction has little
effect on the velocity and they hit the Earth with the enormous speed
characteristic of their entry into our atmosphere.
Thus, it is estimated that the meteorite that produced the
Barringer Crater was still traveling at 11 km/second when it struck what
is now the Arizona desert 49,000 years ago that must have caused the
enormous damage. Though the fears are not unfounded, occasional damage to
property, livestock and even people been hit by the meteorites has been
reported. Like the incidence in Alabama where Ann Hodges was struck by a
meteorite while she was in her living room. Also there were reports by
some people in Kentucky of seeing a fireball streaking across the sky.