A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Amateur Astronomy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Solstice December 2018



 
 
Thread Tools Display Modes
  #1  
Old December 19th 18, 07:54 PM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default Solstice December 2018

The great forward motion of the Earth through space has turned the North and South Poles to their appointed positions on the Solstice -

https://epic.gsfc.nasa.gov/

The area where the Sun is constantly in view is about to reach its maximum circumference (Antarctic circle) while its Northern counterpart the opposite is in operation.

At lower latitudes, apart from the Equator, the maximum asymmetries between daylight and darkness are reached before the balances shifts after the Solstice and the slow leveling goes on towards the Equinoxes as the Poles and the entire surface of the Earth turns parallel to the orbital plane.

The people who dump everything into circumpolar motion may not care, however, those who can look into the centre of the solar system and towards our stationary Sun can see the full relationship between our motion and that Sun along with the motion of the faster moving planets -

https://www.youtube.com/watch?v=3VVCiPp67vI&t=30s

However grainy that time lapse is, to see the stars move in isolation and parallel to the orbital plane, it is a true masterpiece for those who genuinely love astronomy.
  #2  
Old December 21st 18, 04:58 AM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default Solstice December 2018

Today marks the great astronomical event of two distinct noon events and two midnight events, one daily and the other polar within the same 24 hour day.

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

The distance between that location and the circle of illumination is now at a maximum giving rise to the Antarctic circle where the Sun is now constantly in view across the largest area with the South Pole at the centre -

https://www.youtube.com/watch?v=-OgLCH7jYp8

The orbital plane cuts through the maximum diameter of the Earth and represented by the broken line in the following graphic -

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

The orbital surface rotation at the maximum circumference is, on average, about 68. 2 miles per 24 hour day. At the North and South Polar latitudes, that speed reduces to 30 miles per day consistent with the original perspective of Copernicus -

"The third is the motion in declination. For, the axis of the daily rotation is not parallel to the Grand Orb's axis, but is inclined [to it at an angle that intercepts] a portion of a circumference, in our time about 23 1/2°. Therefore, while the earth's center always remains in the plane of the ecliptic, that is, in the circumference of a circle of the Grand Orb, the earth's poles rotate, both of them describing small circles about centers [lying on a line that moves] parallel to the Grand Orb's axis. The period of this motion also is a year, but not quite, being nearly equal to the Grand Orb's [revolution]." Copernicus



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
December Solstice 2016 Gerald Kelleher Amateur Astronomy 10 December 21st 16 06:03 PM
December Solstice 2015 oriel36[_2_] Amateur Astronomy 6 December 21st 15 03:16 PM
December Solstice repost oriel36[_2_] Amateur Astronomy 2 December 17th 13 10:57 PM
The December Solstice oriel36[_2_] Amateur Astronomy 4 December 20th 10 11:42 AM


All times are GMT +1. The time now is 03:15 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright 2004-2024 SpaceBanter.com.
The comments are property of their posters.