* Astronomy

Blobrana · L

RE: Xochicalco observatory

Blobrana · L

The Observatory of Xochicalco is an underground, cave-like room: a hole in the ceiling provides light. During the summer months of late April to August, sunlight comes directly through the hole, illuminating the room. On May 15 and July 29, the sun is directly overhead and illuminates an image of the sun located on the cave floor: these days were obviously very important to the Xochicalco priests.
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Blobrana · L

The observatory is a cave modified to allow study of the movement of the sun. The cave was covered with stucco and painted black, yellow and red with a chimney that measured from the base to the surface 8.7 meters, and which is hexagonal in the top. The chimney has a slight slope allowing the sun's rays to be to projected on the floor of the cave.
In the 105 days running from 30 April to 15 August, the sun shines into the cave. In the sun's movement towards the Tropic of Cancer and upon their return, respectively, on 14/15 May and 28/29 July, the sun is at its zenith and the astronomical noon, the beam of light falls directly through the chimney showing the image of the sun on the floor of the cave.
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