Aurora Over Iowa (APOD 18 Dec 2006)

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l3p3r
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Aurora Over Iowa (APOD 18 Dec 2006)

Post by l3p3r » Mon Dec 18, 2006 7:15 am

That has to be one of the best aurora shots I've ever seen!

http://antwrp.gsfc.nasa.gov/apod/ap061218.html

Is there a higher resolution version to use as a desktop background? :)

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iamlucky13
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Post by iamlucky13 » Mon Dec 18, 2006 9:03 pm

Amazing isn't it? :shock:

I can't believe I've lived in Washington all my life and never noticed an aurora. Would a good show (from a good latitude, of course) really appear as bright and colorful to well-adjusted eyes as this, or do we just benefit from the long exposure? The stars in the picture, for example, seem a reasonable naked-eye brightness.
"Any man whose errors take ten years to correct is quite a man." ~J. Robert Oppenheimer (speaking about Albert Einstein)

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iamlucky13
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Post by iamlucky13 » Mon Dec 18, 2006 9:06 pm

Oh, by the way, the APOD caption provided a link to the photographer's personal web site. There's more amazing shots of the same show, but I don't see any larger resolution. I suppose he's interested in selling prints, for which you can hardly blame him.
"Any man whose errors take ten years to correct is quite a man." ~J. Robert Oppenheimer (speaking about Albert Einstein)

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BMAONE23
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Post by BMAONE23 » Mon Dec 18, 2006 10:53 pm

For most Aurora I've seen imaged, they seem to be green on the bottom and red on the top. Is this similar to nebula where energized hydrogen is red and oxygen is blue/green?

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orin stepanek
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Post by orin stepanek » Tue Dec 19, 2006 3:34 pm

Here's some from an earlier post.
http://asterisk.apod.com/vie ... php?t=7436
Orin
Orin

Smile today; tomorrow's another day!

kovil
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a short lecture

Post by kovil » Tue Dec 19, 2006 11:11 pm

In Canada once or twice in the summer the lights show up, partly because the days are so long. I haven't been there in the winter, it's too cold.
A tan light or green and it shifts slowly. At first I thought it was just city light reflected on the clouds, but there's no city in that direction. I've seen it in Nevada twice in 12 years. Great illumination in the north, which is open land for 200 miles. Not spaceships. Northern lights !!
They move slowly in Canada, if I look away for 10-30 seconds and then look back I can see it is different, but if I just look at it , it stays the same and doesn't change.

here's an attempt to explain them; a handout for those interested partys at parties of non-science oriented folks.

Causes of the Northern Lights


The Northern Lights, or Aurora Borealis, are glowing bands, circles and streams of colored lights that sometime appear in northern latitudes. The southern hemisphere has similar light shows that are called Aurora Australis or the Southern Lights. Both Northern and Southern Lights are referred to collectively as Aurora Polaris. The lights can span the visible, infrared and ultraviolet spectrum, and vary in intensity, duration and extent. They can last a few minutes or all night; Northern Lights can also occur during the day, but sunlight makes them un-visible.

The Northern Lights are caused by activity on the sun. Strong magnetic activity is continually taking place on the surface of the sun, and electrons and ions are constantly being thrown out into space. This ‘plasma’, called the solar wind, is ejected in all directions. It is only when a strong solar wind blows in our direction that Northern Lights occur.

Because electrons and ions (the atom’s nucleus without all the electrons), are electrically charged particles, they are influenced by the magnetic field of the earth, which sweeps them up as they approach and funnels them toward both poles. The particles spiral down the ‘polar cone’ of the earth’s magnetic field until they get too crowded and overflow, then spill out and hit the atmosphere, where they interact with atmospheric gases to cause the lights in the sky.

The stronger the ‘storm’ on the surface of the sun, the more particles are ejected into space and potentially reach our atmosphere. The more particles quickly captured by the earth’s magnetic field, the farther south the particles spill out from the overcrowded ‘polar cones’. They are then consumed in an energy absorption/radiation reaction with atmospheric gases. Auroras are visible in the Arctic and Antarctic nightly whenever there are solar storms, and are routinely seen in northern countries with high latitudes. The farther away from the pole you go, the less likely you are to see Northern Lights, with the aerial display being visible at the equator only once every century or two.

The colors of the Northern Lights are indicative of how high in the atmosphere the reaction is taking place. Red lights indicate particles reacting at higher altitudes than green lights.
Since the solar wind is always bathing the earth with particles, there are always some upper atmospheric reactions taking place. It is only when the solar wind is particularly intense that the reaction is bright enough to be seen with the naked eye.

Northern lights originate from our sun. During large explosions and flares, huge quantities of solar particles are thrown out of the sun and into deep space. These plasma clouds travel through space with speeds varying from 300 to 1000 kilometers per second.

But even with such speeds (over a million kilometers per hour), it takes these plasma clouds two to three days to reach our planet. When they are closing in on Earth, they are captured by Earth’s magnetic field (the magnetosphere) and guided towards Earth’s two magnetic poles; the geomagnetic south pole and the geomagnetic north pole.

On their way down from the geomagnetic poles, the solar particles are stopped by Earth’s atmosphere, which acts as an effective shield against these otherwise possibly deadly particles. When the solar particles reach the atmosphere, they collide with the atmospheric gases present, and the collision energy between the solar particle and the gas molecule causes a photon to be emitted. A photon (a particle of light), is emitted when a gas molecule absorbs energy and then re-radiates that energy at a lower frequency; that of visible light. When you have huge numbers of such collisions, you have an aurora. Each different type of gas molecule emits a specific unique color of light.


===

What I really wanted to post about is;

Dec 17, 2006 APOD, where it is suggested that they are measuring Dark Energy or substantiating it's existence. I say NO, not dark energy; what is being detected or measured or observed is ENTROPY !!

==

from: H.H.S.Tagaard's - Ode to the Infinite

. . . they measured entropy
and thought it was Dark Energy.

they built synchrocyclotrons
and thought they had discovered the Zo particle.

they built focused bejingowatt lasers
and thought they could accomplish fusion.

What they mistakenly didn't see is All is wave-function energy artifacts,
what the search is for is what controls the energy wavefunction in the primary place.

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