Ancient Maya ruins reveal 1200-year-old astronomical tables

As part of an urban renewal project circa 800 CE, Maya inhabiting what is now the Petén region of Guatemala filled residential dwellings with rubble and dirt before building over them. A structure’s walls in the now-excavated Xultún complex have recently provided a multidisciplinary team led by archaeologist William Saturno of Boston University with an intellectual treasure: two tables, apparently of ancient astronomical reckonings. One table of hieroglyphs includes dozens of columns each with three digits. Most columns are illegible, but the final three—all of which have Moon glyphs above the digits—evidently represent a sequence of numbers separated by 177 or 178, corresponding to the number of days in the Maya “semester” of six lunar months. The second table has four columns; each of those presents a glyph above five digits that express a base-20 number. Digital enhancement of the section of wall shown in the figure revealed the indicated hieroglyphs. The large numbers in each column are related to important Maya time periods, including the 365-day year. But each number is also an integer or half-integer multiple of the synodic periods (apparent orbital periods as perceived from Earth) of Venus and Mars. Codices dating from 1300 to 1521 CE, write Saturno and colleagues, show that the Maya sought harmony between astronomical events and sacred rituals. The Xultún tables, they continue, may have been inspired centuries earlier by the same desire. (W. A. Saturno et al., Science 336, 714, 2012. )—Steven K. Blau