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Old March 19th 18, 08:14 PM posted to sci.astro.amateur
Gerald Kelleher
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Default The Equinox defined

Even in geocentric terms the Equinox is a special day with two distinct types of sunrises and sunsets.

The Sun will come into view for the one and only time this year at the North pole after it set last September while the Sun will turn out of view at the South pole until next September. It represents the fact that if daily rotation and all its effects are subtracted, the entire surface of the planet turns once to the Sun each year as a function of the Earth's orbital motion.

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


The time lapse presently should show a mirror image where the polar points are at opposite sides of the fully illuminated Earth generating a mirror image but sadly the organization in charge of this satellite decide to give the Earth a zero degree inclination presently -

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


Once again, the Sun doesn't cross any celestial equator tomorrow within a celestial sphere - the Earth turns in two different ways to the Sun thereby generating the planet's two day/night cycles. Tomorrow is special as there is 24 hour sunrise/sunset and Polar sunrise/sunset, something that happens only once a year at the latter location.