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Meteors and Comets
Meteors
• On a clear night, one can see “shooting stars”. These are
not stars, but meteors.
• They are debris and dirt particles from outer space (Pieces
of rock that may come from a star or another heavenly body)
that have strayed into the earth’s atmosphere.
• They are the only members of the solar system that do not
orbit anything
• The earth or any other planet attracts meteors by their
gravity, but as they fall to the earth, they burn up in the
atmosphere and look just like a shooting star
• If they are big enough, they will not totally burn up and will
hit the earth. Meteors that survive are called METEORITES
• Meteorites can cause damage. When they hit the earth they
create CRATERS, just like on the moon. The earth has been
hit by millions of meteorites in the past, their craters have
eroded away.
• If it wasn’t for the atmosphere, the meteors would not burn
up before they hit us and if they did hit us there would be no
erosion and the earth would be full of craters like the moon
A meteor impact
created the circular
basin occupied by Lake
Manicouagan in the
Canadian Shield
(Quebec), 214 million
years ago. The original
crater was 100 km in
diameter.
Comets
• They are members of the solar system
• Their orbit around the sun in very eccentric orbits
• Most comets actually leave our solar system. Some exist in
the Kuiper Belt just outside of Pluto
• When comets are close to the sun, we on Earth can see them
as small balls of light each with a long tail streaming out
behind
• A comet is made out of two parts:
a) Head
b) Tail
• ‘Head’ is made up of billions of particles of dust and rock
and it shines by reflected light.
• ‘Tail’ is made up of gas and gives off its own light and it
points away from the sun due to the pressure of solar winds.
• The most famous comet is Haley's Comet. In 1705 Edmund
Haley predicted that a comet seen in 1531, 1607, and 1682
would return in 1758. He was right. Halley’s Comet passes by
the earth every 76 years. The last time it did was in 1986.