Meteoroids

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Meteoroids burn up in the atmosphere and fall to the Earth as dust. Every day, approximately 3000 metric tons of dusty space material falls to Earth.

A meteoroid is a piece of stony or metallic debris which travels in outer space. Meteoroids travel around the Sun in a variety of orbits and at various speeds. The fastest meteoroids move at about 42 kilometers per second. Most meteoroids are about the size of a pebble. When one of these pieces of debris enters the Earth's atmosphere, friction between the debris and atmospheric gases heats it to the point that it glows and becomes visible to our eyes. This streak of light in the sky is known as a meteor. Most meteors glow for only a few seconds prior to burning up before hitting the Earth's surface. On most dark nights, meteors can be seen. The chance of seeing a meteor with the unaided eye increases after midnight. People often refer to meteors as "falling" or "shooting" stars. The brightest of the meteors are called fireballs. Sonic booms often follow the appearance of a fireball just as thunder often follows lightning. At certain times of the year, more meteors than normal can be seen. When the Earth passes through an orbiting stream of debris from a comet that has broken up, what's known as a meteor shower occurs. Meteor showers take place on about the same dates each year.

A meteor
Peekskill Fireball
The Willamette meteorite
The Willamette meteorite
If the meteor does not burn up completely, the remaining portion hits the Earth and is then called a meteorite. Over 100 meteorites hit the Earth each year. Fortunately, most of them are very small. There has only been one report of a "HBM" (hit by meteorite), and that occurred in 1954. Ann Hodges of Sylacauga, Alabama was slightly injured when a 19.84 kilogram meteorite crashed through the roof of her home. The larger meteorites are believed to have originated in the asteroid belt. Some of the smaller meteorites have been identified as moon rock, while still others have been identified as pieces of Mars. Large meteorites that crashed onto the Earth long ago made craters like those found on the Moon. The Barringer Meteorite Crater near Winslow, Arizona is believed to have been formed about 49,000 years ago by the impact of a 300,000 ton meteorite. The Hoba iron meteorite is the largest single meteorite known. Its present weight is estimated at 66 tons. Part of the Hoba meteorite has rusted away, therefore it's original weight may have been as much as 100 tons! It has never been removed from its landing sight in Namibia. The largest single meteorite found in the United States is the fifteen ton Willamette (Oregon) iron meteorite found in 1902.

A Question

How do meteorites differ from meteors and meteoroids?

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The Answer
The Answer

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