At Chaco Canyon, Anna Sofaer discovered the Fajada Butte, which was a calendar used used to tell time. This calendar made out of three large sandstones, which were engraved with two spiral petroglyphs that indicated solicits and equinoxes. During summer solstice, a beam of light appears at the top of the large spiral and slices it in equal halves. During winter solstice, two beams of light frame the large spiral. Whereas in equinoxes, the light beam slices through the centre of the small spiral and the right side of the large spiral. Therefore, Soafer’s discovery reveals that the Fajada Butte was a calendric system that was necessary to observe or celebrate the solicits and equinoxes, which played play an important role in ancient society.
The Fajada Butte Calendar was also essential for agriculture and religious activities in the Chaco Canyon. Archeologists found strong evidence that suggested religious practices among the ancient people. Many ceremonial platforms were discovered at Pueblo Bonito, which is located at the centre of Chaco Canyon. Furthermore, many artifacts related to religious ceremonies were discovered inside Pueblo Bonito. Archeologists found broken pottery (ritual offerings), ceremonial sticks and copper bells. Therefore, this evidence shows that the Fajada Butte Calendar was used to schedule religious activities. The Fajada Butte Calendar is also important for agriculture. The film, Mystery of Chaco Canyon, mentioned that food was sacred in the ancient life because it did not grow easily due to weather conditions and short growing seasons. Hence, the ancient people built the Fajada Butte Calendar to observe the occurrence of summer and winter solstice in order to harvest crops for food.
At the Chaco Canyon, archaeologists also discovered that many buildings aligned with each other. However, these building also aligned with the solar, lunar, equinox, and solstice cycles. For example, Pueblo Bonito is positioned to face the rising and setting moon and during lunar standstill the moon is located between the doorway of the building. The ancient people had no utilitarian purpose of developing these alignments. Therefore, this suggests that this complex astronomical pattern was built to develop a cosmological expression in the Chacoan region. Furthermore, the ancient people had the buildings align so they could observe the same astronomical phenomenon from different locations. For example, people at Chimney Rock Pueblo could see the moon ascending and people hundred kilometres away at Fajada Butte would see the moons shadow on a spiral. The ancient people are located many kilometres apart, yet they are united by the astronomical phenomena. Therefore, the celestial design of the structures were important because they connected solar and lunar cycles and people over a great distance. In conclusion, Fajada Butte and the alignment of buildings suggest that the solar and lunar cycles played an important role in Chacoan culture.