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Where noon comes only once a year

At Earth’s South Pole, high noon comes only once a year, on the December solstice. Meanwhile, the North Pole is getting its only midnight.

Question: Where on Earth does noon only come once a year?

Answer: At the South Pole, and it happens on the December solstice.

That’s if we define “day” by successive noons (successive sunsets, successive midnights or successive sunrises). Using that definition, a day lasts a year at the North and South Poles. Sunrise comes every year around the spring equinox, noon at the summer solstice, sunset around the autumnal equinox and midnight at the winter solstice.

Meanwhile, on the December winter solstice, it’s midnight at the other end of the world, at the Earth’s North Pole. According to the definition of “day” above, midnight comes only comes once a year for the North and South Poles,.

Some three months after the December solstice, around the March equinox, the sun will finally set at the South Pole and rise at the North Pole. Some six months after the December solstice, at the June solstice, it’ll be noon at the North Pole and midnight at the South Pole. Nine months after the December solstice, around the September equinox, it’ll be sunrise at the South Pole and sunset at the North Pole.

At the December solstice, the sun is shining at zenith (straight overhead) at the tropic of Capricorn, at which juncture, it is noon at the South Pole and midnight at the North Pole.

At the December solstice, the sun is shining at zenith (straight overhead) at the tropic of Capricorn, at which juncture, it is noon at the South Pole and midnight at the North Pole.

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Bottom line: Here’s a different way of thinking about the word “day.” At the North and South Poles, sunrise comes at the spring equinox, noon at the summer solstice, sunset on the autumn equinox and midnight at the winter solstice.

Bruce McClure

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