Fade to Black
Our sunsets are waxing, but we’ve another month of waning mornings
If the darkness is already dimming your spirits, take heart, as Friday the 7th marks the earliest sunset of the year at 4:45:52. Yes, the shortest day comes with solstice, December 21, and you might expect that to be both earliest sunset and latest sunrise. But physics are not so simple.
First, earth’s orbit around the sun is an egg-shaped ellipse rather than a circle, with the planet picking up speed and its arc narrowing as it nears the sun. Second, the earth is far from spherical, instead bulging at the center and pinched at the poles as it spins on its axis. That axis, tilted 231⁄2-degrees, further complicates the equation, rocking the planet back and forth over the year.
After the 7th, sunset grows later, although at less than one minute over the coming week. Over the same period, the sun continues to rise later, losing almost five minutes of ground with sunrise at 7:13 this week but not until 7:18 seven days later. By the time we reach the latest sunrise of the year, January 5, we’ll have lost another nine minutes of morning light.
All this darkness, combined with the new moon on the 9th, sets a perfect backdrop for gazing skyward.
Mars rises around 6pm, surrounded by the bright stars of the Great Winter Circle. Above the ruddy planet are Pollux and Castor of Gemini; moving clockwise, look for golden Capella to the west of Mars with the red-giant Aldebaran to the south; lower still is blue-white Rigel, the foot of Orion; following the hunter are two brilliant stars, first, Sirius the Dog Star of Canis Major, and then Procyon of Canis Minor. In the midst of it all marking Orion’s shoulder shines Betelgeuse.
Saturn now rises just before midnight and is high overhead by dawn. Venus rises around 4am and blazes in the southeast at daybreak.
Illustration: © Copyright 1925 M.C. Escher/Cordon Art-Baarn-Holland; Graphics: © Copyright 2007 Pacific Publishers. Reprinted by permission from the Tidelog graphic almanac. Bound copies of the annual Tidelog for Chesapeake Bay are $14.95 ppd. from Pacific Publishers, Box 480, Bolinas, CA 94924. Phone 415-868-2909. Weather affects tides. This information is believed to be reliable but no guarantee of accuracy is made by Bay Weekly or Pacific Publishers. The actual layout of Tidelog differs from that used in Bay Weekly. Tidelog graphics are repositioned to reflect Bay Weekly’s distribution cycle.Tides are based on National Oceanic and Atmospheric Administration and are positioned to coincide with high and low tides of Tidelog.