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Ephemeris: 12/19/2025 – Winter begins Sunday

December 19, 2025 Comments off

This is Ephemeris for Friday, December 19th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:04, and it will rise tomorrow at 8:16. The Moon is new today, and won’t be visible.
The thermometer and snowfall tell us that winter ought to be here. Well, it will be at 10:03 Sunday morning. At that point, the winter solstice, the Sun will be directly over the Tropic of Capricorn at 23 ½ degrees south latitude. It’s an odd name because 2,000 years ago the Sun was in indeed entering Capricornus. Now it will be entering Sagittarius, right above the spout of the teapot asterism we know so well in summer. From then on the Sun will be climbing up the sky each noon until June 21st next year when summer will start. To which I say: Go Sun Go! The Sun will almost make it up to 22 degrees above the southern horizon at local noon, which is 12:40 pm, in Interlochen and be out for only 8 hours and 48 minutes. If it stayed that low all year, we’d be in a deep freeze, possibly colder than Antarctica.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Comparing the Sun's path in the sky for winter and summer solstices
Comparing the sun’s path at the summer and winter solstices. This is a stereographic representation of the whole sky which distorts the sky and magnifies the size of the sun’s path near the horizon.
December solstice
The Earth and its axis on the first day of winter, the winter solstice. From my Sun and the Earth talk slides.
A comparison of the solar heating effect of the Sun at local noon on winter and summer solstices at 45° north latitude. Winter, 37% and summer, 93% of the Sun at the zenith.
A comparison of the solar heating effect of the Sun at local noon on winter and summer solstices at 45° north latitude. This ignored the effect of the thickening atmosphere as the altitude decreases, making the difference even greater. Also, near the summer solstice the Sun is out higher and longer. Created using LibreOffice Draw and GIMP.
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