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| SOL | MERCURY | VENUS | EARTH | METEORS | MOON | MARS | ASTEROIDS | JUPITER | SATURN | URANUS | NEPTUNE | PLUTO | COMETS |
A meteor can be anything from a grain of dust, to a piece of man-made space junk. The official definition of the International Astronomical Union is "a solid object...considerably smaller than an asteroid, and considerably larger than an atom or molecule."
Most meteors are consumed in the fire of friction long before they reach the ground, their annihilation producing a spectacular streak of light across the sky, known as a shooting star. Occasionally, if the meteor is large enough, a piece of it may survive the fireball, and reach the ground. Even more occasionally, this fragment will be found. The meteorite pictured below landed near Murchison, Australia, September 28, 1969.
Below left is a meteorite that fell to Earth near Alexandria, Egypt, on June 28, 1911. The meteorite on the right came down near Vladivostok, Russia, December 2, 1947.
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The most common occurrence of meteors is the result of Earth passing through the debris field of a comet. As comets near the sun, a portion of their icy bodies vapourise, giving rise to their distinctive tail, and leaving behind a debris field of dust and dirt. If the comet passed close enough to Earth's orbit, then once a year, when Earth passes through the debris, we experience a meteor shower. In one complete orbit around the sun, Earth passes through no less than 110 of these debris fields, although most of them produce limited displays. The major, most impressive meteor showers are listed below:
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The dates listed are the times of maximum activity, although meteors may be seen for a few days surrounding those dates. The names of the meteor showers are derived from the constellation where the meteors appear to originate, called the radiant.
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