Cesar Chavez Park; The Interim Solar Calendar
Monday, December 20th; 4:15 to 5:15 pm; Sunset: 4:50
Gathering will be led by Alan Gould, Lawrence Hall of Science
Special Event – weather permitting:
Near Simultaneous full moon rise/sun set around 4:50 pm
Total Lunar Eclipse later than evening (beginning 10:33 PM).
New Installation at the Memorial Solar Calendar Site:
Earth Cycle – Sun Shadow
Cesar Chavez Memorial Solar Calendar
The Meridian Calendar
37° 52′ N Lat / 122° W Long
Light & Shadow Observations: Earth Cycle – Sun Shadow is a temporary installation that combines art, science & cultural education.
Rather than utilizing the horizon as a calendar, a light spot or shadow crossing a noontime meridian also served as a calendar among many ancient civilizations. For example, The Sun Dagger in Chaco Canyon, New Mexico, functions when the sun is near the meridian, rather than on the horizon. Also 17th century European cathedrals utilized a carefully located hole in the roof that would cast a spot of light on the floor of the cathedral along a meridian over the course of a year. At the Solar Calendar site, the shadow from the gnomon will cross the meridian at solar noon. The meridian calendar will allow the observer to witness the movement of the earth by watching the shadow move from west to east. It also has markings indicating shadow length for each month, the beginning of each season, differential seasonal shadow patterns, and the commemoration of the birth of Cesar Chavez.