| The
term meteor comes from the Greek meteoron, meaning phenomenon in the sky.
It is used to describe the streak of light produced as matter in the solar
system falls into Earth's atmosphere creating temporary incandescence resulting
from atmospheric friction. This typically occurs at heights of 80 to 110
kilometers (50 to 68 miles) above Earth's surface. The term is also used
loosely with the word meteoroid referring to the particle itself without
relation to the phenomena it produces when entering the Earth's atmosphere.
A meteoroid is matter revolving around the sun or any object in interplanetary
space that is too small to be called an asteroid or a comet. Even smaller
particles are called micro meteoroids or cosmic dust grains, which includes
any interstellar material that should happen to enter our solar system.
A meteorite is a meteoroid that reaches the surface of the Earth without
being completely vaporized. |
This
meteorite was collected from the Allan Hills in Antarctica. Meteorites
are bits of rock that are captured by a planet's gravity and pulled to
the surface. This meteorite is of a type named chondrite and is thought
to have formed at the same time as the planets in the solar nebula, about
4.55 billion years ago. (pics NASA/JPL)
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