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Polar dawn



 
 
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  #1  
Old August 15th 18, 05:42 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

The first glimpse of Polar dawn are setting in at the South Pole, where, in just over 5 weeks the Sun will come into view for the first time in 6 months as the Earth slowly turns parallel to the orbital plane and as a function of the Earth's orbital motion -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

Pity they have installed a $50 webcam to mark the one and only event of its kind at the South pole each orbit but then again researchers at habitable latitudes are oblivious to the fact that the planet will turn once each orbital circuit to the Sun aside from and in addition to daily rotation.

People those come to appreciate these thing at academic junkets like conferences, they can enjoy the spectacle in their own way and their own time once they give the Polar day/night cycle and its cause consideration. The polar day/night cycle offers a different astronomy due to its unique cyclical traits that exist nowhere else on the planet.

  #2  
Old August 15th 18, 08:14 PM posted to sci.astro.amateur
Quadibloc
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Default Polar dawn

The Earth's Equator is still going to be inclined 23 1/2 degrees to the
orbital plane, the Ecliptic, as always.

What will happen is that the Earth will move to the point in its orbit
around the Sun where the line connecting the Earth and the Sun is
in the direction of the line of intersection of those two planes.
  #3  
Old August 15th 18, 08:49 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

In another month the South pole will cross the circle of illumination and the central Sun will come into view for the first time in 6 months -

https://en.wikipedia.org/wiki/Deep_S...-tilt-23.4.gif

This event is rarely captured and the context of the Polar day/night cycle and its rotational cause has yet to be put into proper mainstream context despite the availability of images from the surface and space -

https://www.youtube.com/watch?v=okw6Mu3mxdM

This event has been going on through all the events and accidents of life on Earth and its oldness in no way takes away from its astronomical uniqueness that can be enjoyed next month as it always will be for those who live in honour and dignity within the greater life of creation -

“The day we see the truth and cease to speak is the day we begin to die” ― Martin Luther King Jr.

  #4  
Old August 16th 18, 03:44 PM posted to sci.astro.amateur
Quadibloc
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Default Polar dawn

On Wednesday, August 15, 2018 at 1:49:19 PM UTC-6, Gerald Kelleher wrote:

“The day we see the truth and cease to speak is the day we begin to die” ― Martin Luther King Jr.


Unfortunately, when it comes to orbital and rotational dynamics in the Solar System, you're Mr. Magoo.

John Savard
  #5  
Old August 16th 18, 07:25 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

The relationship between the polar latitudes and the orbital plane far exceeds the use of the 23 1/2 degree inclination insofar as it prevents the use of a climate spectrum between 90° inclination (Equatorial) and 0° inclination which coincides with the orbital plane and represents a complete polar climate.

http://afewbitsmore.com/img/2015_ecliptic.png

https://en.wikipedia.org/wiki/Deep_S...-tilt-23.4.gif

At the moment the North and South poles turn parallel to the orbital plane at a 66 1/2° inclination while keeping in mind that these represent points of the entire planetary surface turning unevenly as a function of the orbital motion of the Earth.

Rather than the 'tilt' of the Earth causing the seasons, the degree of inclination determines the rate of change in surface conditions over half or a full orbit, the closer to the orbital plane the more pronounced that rate of change is while an inclination at a right angle to the orbital plane (90°) generates no change throughout an orbit.


I would always be gracious to those who would make an attempt to model or simulate conditions using actual observations but have no time for indiscriminate simulation for the sake of cartoon conclusions as under-developed adults are wont to do.




  #6  
Old August 18th 18, 07:25 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

There is an entire area of research being ignored as the reflected light of the moon meshes in with the polar day/night cycle. Presently the soft reflected light of the moon phase mixes with the aurora, the observable stars and polar dawn at the South pole as that polar location approaches the circle of illumination -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm


The polar night is not a simple 6 months of darkness no more than day/night at habitable latitudes is complete darkness however the separate day/night cycles from separate rotational causes display unique traits. Of course it doesn't help that the South Pole webcam appears incidental to research but for those who genuinely have a feel for astronomy on a more expansive level that is said with dismay rather than anger.

  #7  
Old August 19th 18, 11:28 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

The reflected light of the moon at the Polar latitude generally highlights the so-called 'Rule of Twelfths' as the change is more pronounced away from New Moon or Full Moon -

https://www.moongiant.com/phase/08/19/2018

https://en.wikipedia.org/wiki/Rule_of_twelfths

It happens also in other areas of research such as the Solstices, tides and so on hence is far more relevant than the equalising of orbital geometries based on their periods and distance from the Sun. It is also more relevant to engineering as an object reaches it maximum height before falling so it is this observation that has more relevance than Kepler's comments on comparative orbits.



  #8  
Old August 21st 18, 08:33 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

So far as it is possible to draw observers attention to astronomy at the South Pole where motions are stretched out, the reflected light of the near full moon and its orbital position turns the polar latitude into full brightness -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

https://www.moongiant.com/phase/08/21/2018

When the moon shifts its orbital position closer to the Sun in its monthly orbit
around the Earth as denoted by its circle of illumination, light from polar dawn will have flooded the landscape as that location approaches the circle of illumination.
  #9  
Old August 23rd 18, 07:28 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

Very few things as beautiful as the polar dawn presently, a unique planetary event that few in society here about -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

Observations can never be replaced with words many times and this is one of them.
  #10  
Old August 23rd 18, 07:31 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Polar dawn

The glimpse of polar dawn presently is both unique and beautiful within 4 weeks of the first appearance of the Sun -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

Sometimes no words can approach observations and perhaps the long polar dawn is one of them.

 




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