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Hundreds
of miles above our planet is a huge ocean of air. We know it as
the atmosphere, and it contains many gases. The northern and southern
lights are caused by very high speed particles, from the Sun striking
these gases. These particles make the gases glow.
This deed is comparable to
what happens when you turn on your TV. At one end of the picture
tube is a source of electricity that is made up of minute invisible
particles known as electrons. As the electrons go through one end
of the tube, magnets haul them to the other end. There they strike
chemicals on the back of the T.V. screen, making them glow. Images
then appear on the screen. That is simply how it works.
For thousands and thousands of years, people all over the world,
have watched the sky with astonishment as it burst into auroral
light, and wondered if the lights were magic. Over time, people
all over have come up with their own explanation for the sky’s
auroral lights. In Asia, some used to think the lights were to great
dragons battling in the sky. Russian tales said that the spirits
were lighting the way for the birth of a new child. To some Scandinavians,
the presence of auroras in the sky indicated a change of good luck.
American Indian legends interpreted red auroras as the fires of
enemies preparing for a battle; white auroras are the torches of
spirits fishing at night. New Zealand natives considered auroras
as the campfire of lost souls. As recently 50 years ago, people
believed that the lights were no more than reflections of sunlight
or moon light bouncing off the Artic ice pack or off ice crystals
floating in the atmosphere. In 1619, the Italian astronomer Galileo
named the glow he saw in the sky “Aurora,” after the
Roman goddess of dawn.
The lights around the North Pole are now called the aurora borealis.
The rings of the southern lights are the aurora the “dawn
of the north.” Northern lights and the “dawn of the
south.”
In 1968, an airplane took off from Anchorage, Alaska. At the same
time, another airplane took off from Christchurch, New Zealand.
The two planes flew to equivalent altitudes above the North and
South Poles and began taking pictures. These pictures, taken at
the exact same time show the exact same design, patterns and movements
of the auroras. They proved what had long been suspected-not only
do auroras come to both poles at the same time, they mirror each
other. That is, a person in the north can see the same auroral designs
as a person in the south.Although people used to believe that all
auroras were supernatural, we have found they are as natural as
the moon. In a way they are a part of the sun and the air. Auroras
have their beginnings in storms on our sun. These storms are accompanied
by giant violent explosions, called solar flares.
Color
Although auroras can be any color, we see mostly soft light greenish
auroras.
This color comes when atoms of oxygen in the in the atmosphere are
struck by electrons from the sun. Different gases glow different
colors when exposed to an electrical charge. Sometimes, (but not
very often) there bon of red or purple on the lower edge of the
aurora. This color comes from molecular nitrogen. Nitrogen glows
red, purple, or even blue!
To learn more go to: The book,
"Light Shows in the sky, AURORAS"
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