Olmec E-Groups Tracked Astronomical Events, 260-Day Calendar Dated to 1100-750 BCE. E-groups are architectural formations with western pyramid facing eastern platform across a plaza Functioned as astronomical observation platforms for tracking sun movements, solstices, and equinoxes Orientations marked sunrise dates of February 11th and October 29th
Olmec E-groups were astronomical observation platforms featuring western pyramids facing eastern platforms across plazas. These structures tracked solstices, equinoxes, and sun movements, with orientations marking sunrise dates of February 11th and October 29th—a 260-day interval matching the famous Mesoamerican calendar. The calendar combined 13 numbers with 20 day names (13 x 20 = 260) and dates to 1100-750 BCE. Some platforms featured 20-edge designs (20 being the base unit of Mesoamerican calendars). Evidence also shows tracking of moon and Venus movements, with Venus later associated with warfare, sacrifice, and fertility through its synchronization with agricultural cycles.
Key Facts
- E-groups are architectural formations with western pyramid facing eastern platform across a plaza
- Functioned as astronomical observation platforms for tracking sun movements, solstices, and equinoxes
- Orientations marked sunrise dates of February 11th and October 29th
- Interval of approximately 260 days indicates use of the Mesoamerican 260-day calendar
- Calendar was in use between 1100 and 750 BCE
- Several sites feature 20-edge platforms (number 20 is base unit of Mesoamerican calendars)
- 13 numbers combined with 20 day names create 260 unique combinations (13 x 20 = 260)
- Evidence also shows tracking of moon and Venus movements
- Venus was personified as a deity, later associated with warfare and sacrifice
- Venus synchronization with agricultural activities suggests association with fertility
Source: The OLMECS: Everything You Need to Know by World of Antiquity