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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
The mass extinction of the Dinosaurs has been linked to a
meteor (or asteroid) impact. The impact was so large that it
sent water and dust into the atmosphere for years. This
water and dust blocked the sun’s rays and changed the
climate below. The plant and animal life were all affected to
the point that most plants and animals died. This could
happen again. The impact is thought to have been in the
Yucatan peninsula off the coast of Mexico. Hollywood has
filmed this type of disaster many times!
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 Halley'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.
THE END!
Check out this neat website. It shows
how Pluto’s plane of orbit is “wonky”
and the orbits of the comets around
the sun.