The noon mark tells us when it is noon. For many centuries the primary means of telling time was the sundial and the noon mark was the most common time observed. Each day men and woman looked to the noon mark to know when to pause for dinner and rest. Many old castles, palaces, churches, homes and gardens still have noon marks. Noon marks lie along the meridian, the north south line running between the North and South Pole, also known as longitude. The longitude of the Memorial is 76.877 degrees west, the angular distance west of Greenwich, England.
The primary elements of the American Civil War Memorial are aligned in an axis along the meridian. The Star Stone lies at the north end of the axis, at the south end is the flag pole. In between, along the same axis, are the portal and the North South Cenotaph. When the shadow cast by a vertical object, such as the Memorial flag pole, is precisely over the meridian it is local apparent noon. Three astronomically significant noon marks have been permanently marked along the meridian on the lawn of the Memorial. The Summer Solstice noon mark is indicated by a red circle incised on a rectangular piece of Pennsylvania blue stone located between the flag pole and the North South Cenotaph. The noon mark stone for the Spring Equinox (blue circle) and the Fall Equinox (gold circle) is located between the portal and the North South Cenotaph. The Winter Solstice noon mark (unmarked) falls in the middle of the south face of the Star Stone.
Equinox and Solstice Dates:
2009 ~ March 20, June 21, September 22 and December 21
2010 ~ March 20, June 21, September 23 and December 21
2011 ~ March 20, June 21, September 23 and December 22
2012 ~ March 20, June 20, September 22 and December 21
2013 ~ March 20, June 21, September 22 and December 21
2014 ~ March 20, June 21, September 23 and December 21
2015 ~ March 20, June 21, September 23 and December 22