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Archive for December 20, 2024

Ephemeris: 12/20/2024 – Winter is coming tomorrow!

December 20, 2024 Comments off

Dec 20. This is Bob Moler with Ephemeris for Friday, December 20th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:04, and it will rise tomorrow at 8:17. The Moon, 2 days before last quarter, will rise at 10:55 this evening.

Today is the last full day of autumn. Tomorrow at 4:40 a.m. winter will begin as the Sun passes the winter solstice and stops its southward movement in the sky. Immediately it will slowly climb northward again. It will lengthen the daytime hours and increase the power of the Sun as it gets higher in our sky. The cooling of the Northern Hemisphere will continue until late January, on average, until the lengthening days and increased solar altitude will finally overcome it. Ancient cultures weren’t all that sure that the Sun would come back, since they didn’t understand what was really happening. So when the solstice finally arrived it was a time for great celebrations which survive to this day.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

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. Created using my LookingUp app.
This is the position the Sun will be, against the stars, at 4:40 AM tomorrow, at the point we call the winter or December solstice
This is the position the Sun will be, against the stars, at 4:40 AM tomorrow, at the point we call the winter or December solstice. The Sun will be at its farther south of the celestial equator, which is the blue line near the top of the image. The orange line that the Sun is on is the ecliptic or its apparent path in the sky. It is traveling eastward or to the left, as it slowly climbs northward to the vernal equinox in March. Created using Stellarium.
Categories: Ephemeris Program, Seasons Tags: ,