Bob Moler's Ephemeris Blog

Ephemeris for Friday, September 20th.  The sun will rise at 7:27.  It’ll be up for 12 hours and 15 minutes, setting at 7:43.   The moon, 1 day past full, will rise at 8:11 this evening.

At 4:44 in the afternoon Sunday autumn will begin.  More important and sad for me is that summer will also end.  Since March 20th the sun has been north of the celestial equator, shining directly over some part of the northern hemisphere tropics, but Sunday it moves south of the equator, causing sunset at the north pole and sunrise at the south pole. That point in time is called the autumnal or September equinox.  In a few days daylight hours here will drop below 12 hours and keep on dropping until we near Christmas.  On a brighter note: During the day Saturday, that’s tomorrow, the Grand Traverse Astronomical Society will have their telescopes down at Fishtown for the Leland Heritage Celebration, that’s 10 am to 5 p.m. in Leland Michigan.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum

The Earth looking from the direction of the sun at the moment of the Autumnal Equinox, 4:44 p.m.EDT September 22, 2013. Created using Celestia.

GTAS at Fishtown in 2011.