The Mayans star, sky and heavenly bodies observations were amazingly accurate. At that time, Mayans did not have telescopes. The observations had to be done with bare eyes. Their information was based on material that had been collected in dozens of systematic ways. Over generations of time their observations from the observatory changed. Their calendars were books full of astrological information. Women and men who created the calendars based them on astronomy. They knew that the universe was on circuit. They predicted even the eclipses of the sun.