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Asteroids
Asteroids are pieces of metallic rock
floating in space. Many asteroids are found in the the space between
the orbits of the planets Mars and Jupiter. This space is known
as the 'asteroid belt'. However some asteroids are found outside
the 'asteroid belt'.
There are probably hundreds of thousands of asteroids in space. The largest one that scientists know about is called Ceres. It has a diameter of 933 kilometres.
Ceres was discovered on January 1, 1801, by Giuseppe Piazzi
One kind of asteroid, called Apollo asteroids, cross the orbit of the earth as they move around the sun. Scientists think that an Apollo asteroid struck the Earth about 90 million years ago in the time of the dinosaurs.
Asteroids that collide with Earth are called meteorites.
See images of asteroids
in space here
http://nssdc.gsfc.nasa.gov/imgcat/thumbnail_pages/asteroid_thumbnails.html
Read more about asteroids here
http://www.spacetoday.org/SolSys/Asteroids/Asteroids.html
Is it possible
that a large asteroid could strike the Earth one day?
Read about the likelihood of an asteroid collision
with Earth here http://whyfiles.org/106asteroid/
If you use any part of this in your own work, acknowledge this source in your bibliography like this:
Thomas, R. & Sydenham, S. Asteroids [Online] www.kidcyber.com.au (2002)
Updated © [2008] kidcyber