Summer Solstice in Pictures

After I completed my 5:30 exercise class at Hampshire Fitness, I made my way back to UMass, to the Sun Wheel on Rocky Hill Road near the Stadium. Today is the Summer Solstice (the exact time was 1:16 pm), and inasmuch as I was in town, and the weather had settled into “mostly clear and mild,” I wanted to attend the 7:30 educational program again. As it happened, I joined the second largest crowd ever — 163 of us, plus 3 dogs — to witness the sun setting (the largest crowd was 223 people in 2002).

Dr. Judith Young bubbles with enthusiasm when she talks about the Sun Wheel project, and what she has done really is remarkable. Faithful readers of my blog will recall that I attended the Summer Solstice gathering in 2008 and wrote extensively on what I learned. I don’t want to repeat myself, so I’ll self-reference here, and then go on to talk about the moon.

The Sun Wheel includes a unique feature: Moonstones. These additional standing stones, next to each of the solstice stones and 1-2′ shorter in height, mark the extremes in the rising and setting direction of the Moon. According to Dr. Young, the Moon’s movement is more complex than the sun’s for several reasons: (1) the Moon does in a month (29.5 days) what the sun does in a year (365.25 days) , namely, make a complete orbit around its parent body, and (2) the Moon orbits us in a plane which is tilted by 5.1° relative to the ecliptic.

Dr. Young noted that the calendrical structure built by the Native Americans of the southwestern United States, atop Fajada Butte in Chaco Canyon, New Mexico, indicated that they understood these aspects of the lunar cycle: (1) The Moon at times can be seen to rise and set more northerly and more southerly even than the solar extremes, and (2) Due to the effects of the sun’s gravity, the Moon’s orbital plane does not stay fixed in space, but “precesses” with an 18.6 year cycle. In other words, “the 18.6 year lunar cycle is observed as a modulation in the outer extremes of the Moon’s monthly range of rising and setting.” The most recent peak of the 18.6 year cycle happened in 2006; this period is known as the Major Lunar Standstill, when the Moon’s declination (effectively the latitude on the sky) ranges each month between -28 and +28°. The Minor Lunar Standstill, when the Moon’s declination ranges each month between -18 and +18°, happens 9.3 years after the Major. To me, this sounds rather abstract, which is why I think having large stones set up to track the moon’s rising and setting is a good idea!

If you went back and read my previous Solstice post, you might be glad to hear that this time around my camera was working and I have these pictures to show you.