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| Aurora Borealis |
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http://www.hemmy.net has more interesting
stuffs as well.
Tags : aurora |
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Affichage : 431790
Durée : 73 s |
| Aurora Borealis / Educational Video |
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Aurora Borealis / Educational Video. NASA
Connect - DITNS - Aurora Borealis. This work
is licensed under a Creative Commons
Attribution 2.5 License. NASA Connect Segment
exploring the Aurora Borealis or Northern
Lights. This segment exlains this natural
phenomena and its history. Year: 2004.
Keywords: Aurora Borealis; Northern Lights;
Artificial Aurora; Terrella; Magnetism;
Earth; Electrons; Natural Phenomena; Plasma;
Solar Wind; Light Particles; Atmospheric
Gases; Duration: 00:04:39; Sponsor: NASA;
Contributing Organization: NASA. Auroras
(North/South Polar Lights; or aurorae, sing.:
aurora) are natural colored light displays in
the sky, usually observed at night,
particularly in the polar zone. They
typically occur in the ionosphere. Some
scientists call them "polar auroras" (or
"aurorae polares"). In northern latitudes,
the effect is known as the aurora borealis,
named after the Roman goddess of dawn,
Aurora, and the Greek name for north wind,
Boreas. It often appears as a greenish glow
or sometimes a faint red, as if the sun was
rising from an unusual direction. The aurora
borealis is also called the northern polar
lights, as it is only visible in the North
sky from the Northern Hemisphere. The aurora
borealis most often occurs from September to
October and from March to April. The Cree
call this phenomenon the Dance of the
Spirits. Its southern counterpart, the aurora
australis/southern polar lights, has similar
properties. Australis is the Latin word for
"of the South". Benjamin Franklin first
brought attention to the "mystery of the
Northern Lights." He theorized the shifting
lights to a concentration of electrical
charges in the polar regions intensified by
the snow and other moisture. Auroras are
produced by the collision of charged
particles from Earth's magnetosphere, mostly
electrons but also protons and heavier
particles, with atoms and molecules of
Earth's upper atmosphere (at altitudes above
80 km). The particles have energies of 1 to
100 keV. They originate from the Sun and
arrive at the vicinity of Earth in the
relatively low-energy solar wind. When the
trapped magnetic field of the solar wind is
favourably oriented (principally southwards)
it reconnects with Earth's magnetic field,
and solar particles enter the magnetosphere
and are swept to the magnetotail. Further
magnetic reconnection accelerates the
particles towards Earth. The collisions in
the atmosphere electronically excite atoms
and molecules in the upper atmosphere. The
excitation energy can be lost by light
emission or collisions. Most aurorae are
green and red emission from atomic oxygen.
Molecular nitrogen and nitrogen ions produce
some low level red and very high blue/violet
aurorae. The light blue colors are produced
by ionic nitrogen and the neutral nitrogen
gives off the red and purple color with the
rippled edges. Different gases interacting
with the upper atmosphere will produce
different colors, caused by the different
compounds of oxygen and nitrogen.
Tags : aurora borealis northern lights magnetism electrons solar wind plasma light particles earth atmosphere gases science USA |
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Affichage : 5079
Durée : 279 s |
| Aurora Borealis-WI |
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Aurora Borealis over northern WI, September
2005. Time lapse of 2 hours, one shot every
35 seconds, each shot a 30s exposure with a
Canon 1Ds Mark II camera and 17-40mm f/4L
lens, f/4, ISO 1600.
Tags : aurora borealis |
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Affichage : 115016
Durée : 28 s |
| RENAISSANCE - NORTHERN LIGHTS - the Aurora Borealis |
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RENAISSANCE - NORTHERN LIGHTS
Destination outward bound
I turn to see the northern lights behind the
wing
Horizons seem to beckon me
Learned how to cry too young, so now I live
to sing
The northern lights are in my mind
They guide me back to you
Horizons seem to beckon me
Learned how to cry too young, so now I live
to sing
Though it's hard away from you
Travelling roads and passing through
It's not for money and it's not for fame
I just can't explain, sometimes it's lonely
Marking the space between the days
Early hours pass away
I sing to you of northern lights
I sing for you of northern nights
Past or future, here or there
Shelter comes in words from you, so talk to
me
I hear your voice, it comforts me
In morning dreams I take your hand, you walk
with me
The northern lights are in my mind
They guide me back to you
Peace enfolds the still night air
Home again I look for you and find you there
Destination homeward now
Take the easy way, bring me down
Making the hard way now I see
Hard to be really free, I'm missing you near
me
Marking the space between the days
Early hours pass away
I sing to you of northern lights
I sing for you of northern nights
Chorus:
The northern lights are in my mind
They guide me back to you
The northern nights are in my eyes
They guide me back to you
Repeat chorus twice
The northern lights are in my mind
They guide me back to you
Tags : RENAISSANCE NORTHERN LIGHTS the Aurora Borealis |
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Affichage : 31139
Durée : 254 s |
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