Did you know?
Fact storyboards in Glacier Ridge, Dollywood
The Aurora Borealis, or Northern Lights, is caused by the solar wind
interacting with the Earth's magnetic field. As the sun shines, it doesn't
just radiate heat and light, but also charged particles that bombard the
Earth constantly. The Earth's magnetic field protects us from these
particles, but at the Poles, where the magnetic field folds in on itself,
the particles interact with the atmosphere, causing the Aurora.
The Aurora usually appear between 60 and 75 degrees of latitude — the
only American state that's that far north is Alaska. During geomagnetic
storms, the Aurora travel much further south. In September 1859, they were
even seen in Honolulu, Hawaii!
The Aurora come in all sorts of colors, from green to blue to red and even
purple. The colors are caused by the charged particles colliding with
different gases in the Earth's atmosphere: oxygen causes the yellow and
green lights, while nitrogen causes red, purple, and sometimes blue. The
colors also depend on how high the collisions happen: blue lights usually
appear below 60 miles altitude, green below 150 miles, and red above 150
Polar Bears are classified as marine mammals, like whales and dolphins,
because they depend so heavily on the Arctic ice pack. However, they are the
only marine mammal that can also travel on land! They are also powerful
swimmers, though: they can hold their breath for three minutes and swim over
one hundred miles.
Polar Bears have been known to visit Brown Bears and Grizzlies further
south, sometimes having children with them. In fact, studies have shown that
the species have probably interbred fairly regularly for some time, as
Grizzlies search northward for food and Polar Bears are pushed off the ice
in the warmer summer months.
Their bodies are very well insulated for swimming in the freezing water of
the Arctic. They have up to four inches of fat under their skin, as well as
a thick hide and two coats of fur to keep them warm. They overheat at
temperatures over 50 degrees Fahrenheit!
The Arctic North is the area near the poles where, in the summer, the sun is
visible at midnight, and in the winter, it's nighttime at noon. It's
delineated by the Arctic Circle at about 66 degrees North of the Equator, or
the very northern parts of Alaska, Canada, Russia, Finland, Sweden, Denmark,
Iceland, and Norway, and most of Greenland. The Arctic Circle is gradually
moving north, however, at a rate of about 50 feet per year.
North of the Arctic Circle, it can be very cold – it regularly gets to -58
degrees Fahrenheit in the winter – but it can also be mild or even warm in
the summer time. In Norway and western parts of Russia, the Gulf Stream
keeps the seas there ice-free all year round, and there have been reports of
summer days reaching 86 degrees!
The word Arctic comes from the Greek arktikos, meaning "Near the Bear." The
bear the ancient Greeks were talking about is Ursa Major, the Great Bear in
the sky, also known as the Big Dipper constellation. Its tail (or handle)
points toward Polaris, the North Star, and has been used for thousands of
years to navigate the world's oceans before people had GPS.