Sun Circle

The Sun Circle is a ceremonial structure in a public park.
In it you can observe the sun’s movement along the horizon over the course of the year.

Eight curving walls create a kiva-like circle  which was inspired by the ruins of Casa Rinconada,  the great kiva at Chaco Canyon in New Mexico, an archeoastronomincal monument,.
Six of the walls have small windows oriented to sunrise and sunset at the summer and winter solstices, and the spring and fall equinoxes.

On those occasions, sunlight passes through the window of one wall and dances along a marked path on a facing wall and across the floor of the circle.

Sunrise on the spring equinox    ⇓

 

When the sun rises on the winter solstice, light pierces through the window in the southeast wall and projects a matching trapezoid of light onto the facing wall.  ⇓

Sunrise on the winter solstice

 

At sunrise and sunset, patches of light follow the tracks marked on the walls and on the floor of the Sun Circle.  (Thanks to Wes Holden for the time-lapse images.)   ⇓

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People on the bike path can stop and take a rest.   ⇓

Sun Circle Bikes

 

Or have a picnic   ⇓

 

People can sit   ⇓

 

or jump   ⇓

 

or measure the precision of the solar tracking   ⇓

 

Or drum up the sunrise   ⇓

 

Or cast shadows on a wall   ⇓

 

Sun Circle

An Archeoastronomical Monument
Tucson, Arizona
Rillito River Park – between La Canada and La Cholla, at Roller Coaster Wash.

In collaboration with Paul T. Edwards and Susan Holman
and Will Grundy, Planetary Scientist

Medium: Split-face block, flagstone, concrete (smooth and exposed aggregate), sunlight.

Percent for Art Program, Pima County Parks and Recreation
and the Pima County Regional Flood Control District.
1994