3. Dresden Codex
The Dresden Codex is a Mayan text dating back around 800 years; it contains 39 beautifully illustrated sheets with texts and images on both sides. Research published in 2016 in the Journal of Astronomy in Culture indicates that the codex records the phases of the planet Venus so that the Maya would be certain that their ceremonial events were being held on the correct day.
The Maya “had a really elaborate ritual set of events that were tied to the calendar,” study researcher Gerardo Aldana, a science historian at the University of California, Santa Barbara, told Live Science. “They were probably doing large-scale ritual activity connected to the different phases of Venus.”
The codex first appeared in Europe at The Royal Library in Dresden, Germany, in the 1730s. How it got there is unclear. Many Mayan texts were destroyed by zealous Christian missionaries trying to wipe out any non-Christian beliefs.