The Sun in Time

Slide Show, Page 3
sun_in_time_ssm.jpg (10439 bytes)
whenge_ss.jpg (3270 bytes)
click on image for a larger version
(11 kB jpeg image)
Photo is courtesy of Tom Sever.
Woodhenge in Cahokia, Illinois is an example of a relatively simple observatory.  Composed of a circular ring with wooden posts inserted at specific intervals, one could stand in the center of the circle and sight along a line intersecting the tall post;  the posts were used to mark the rising Sun on solstices and equinoxes.  These early observatories illustrate the desire of early humans to understand, predict, and perhaps control, the natural world.

Between 700 and 1000 C.E., the Toltec/Maya city at Chichén Itzá flourished.  Located on the Yucatán peninsula of Mexico, Chichén Itzá was home to many ceremonial structures.

One very famous structure is today known as el Castillo (or the temple of Kukulcán).  The "castle" which is seventy-five feet high, is composed of nine platforms with a central stairway on each of the four sides and a top platform.  Since each succeeding platform is narrower than the lower one, the pyramid seems to be much taller.  On the top platform, there is a temple with a doorway facing each of the stairs, but a main door facing north.  From this doorway, the priests could see the plaza below and they could observe processions to the Sacred Cenote (a fresh water sinkhole), which was used for human sacrifice.

Although not an observatory in the sense of the Stone- and Wood- henges, the architecture of el Castillo commemorates three astronomical events: the length of the year, the solstices, and the equinoxes.  The length of the year is represented by the number of steps on the pyramid; there are 91 steps on each of the four sides, totalling 364, with the top platform counting as 1, yielding 365.  An axis through the northeast and southwest corners of the pyramid points to the rising sun on the summer solstice and the setting sun on the winter solstice (this alignment is probable but not substantiated).  Finally, on the day of the equinoxes, the Sun creates a shadow on the side of the steps resembling  an undulating snake (the snake head is bottom right in the image).
cstl_ss.jpg (12341 bytes) click on image for a larger version
(33 kB jpeg image)
Photo is courtesy of Tom Sever.

Press Here for the Next Page

Press Here for the Previous Page

To return to Slide Show Index, click here.

To return to the Sun in Time home page, click here.

This work was paid for by the NASA IDEAS program.

Please direct comments, questions, and suggestions to:
Mitzi Adams
mitzi dot adams @ msfc dot nasa dot gov
(256) 961-7626
Last Updated: April 23, 2014