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Meteoroids, Meteors and Meteorites




Meteoroids

Meteoroids are small pieces of rock or dust that orbit the Sun. These are usually created during collisions between asteroids, which throws off some of the rocky material and sends it into a separate orbit around the Sun.

Meteors

Meteors are the streaks of light seen when meteoroids enter the Earth’s atmosphere at high speed and burn up. Several times a year it is possible to see meteor showers. This is when the Earth passes through the debris left by a comet. These showers can vary in strength, with some giving a few meteors an hour, but others producing a spectacular show of a couple every second. The name of the meteor shower indicates which part of the sky it appears to come from, for example, the Perseid shower appears to originate in the constellation of Perseus.

Shower Date of
Maximum  
Approximate  
Hourly Rate
Quadrantids Jan 3/4 100
Lyrids April 21 10
Eta Aquarids May 5 35
Delta Aquarids (south)
(north)
July 29
Aug 6
25
10
Perseids Aug 12 80
Orionids Oct 20-22 25
Taurids Nov 5 10
Leonids Nov 17 10
Geminids Dec 13 100
Ursids Dec 23 10


Meteorites

An iron meteorite found in the Antarctic Meteor Crater in Barringer, Arizona Meteorites are meteors that reach the ground. They are usually made of rock or iron. About 40-50 tonnes of debris enters the top of the Earth’s atmosphere every day, but atmospheric friction causes it to burn up so that only about a tonne reaches the ground. When a particularly large meteorite strikes the ground it will form a crater. An example of this is Meteor Crater in Arizona. The crater itself measures 1.2 km in diameter and 175m in depth. It was created 50 000 years ago by a meteorite only about 50m across.



Planets Introduction

Mercury

Venus

Earth

The Moon

Mars

Jupiter

Saturn

Uranus

Neptune

Pluto

Asteroids

Comets

Extra-Solar Planets



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Authors: Carolyn Brinkworth and Claire Thomas

Last updated: July 2001