Timeline of astronomy

This is a timeline of astronomy. It covers ancient, medieval, Renaissance-era, and finally modern astronomy.

Mayan astronomers discover an 18.7-year cycle in the rising and setting of the Moon. From this they created the first almanacs – tables of the movements of the Sun, Moon, and planets for the use in astrology. In 6th century BC Greece, this was also discovered

Thales of Miletus is said to have predicted a solar eclipse. He said "it will happen today."

Anaxagoras produced a correct explanation for eclipses and then described the Sun as a fiery mass larger than the Peloponnese, as well as attempting to explain rainbows and meteors. He was the first to explain that the Moon shines due to reflected light from the Sun.

Around this date, Babylonians use the zodiac to divide the heavens sexagesimally into twelve equal segments of thirty degrees each, the better to record and communicate information about the position of celestial bodies.

Plato, a Greek philosopher, founds a school (the Platonic Academy) that will influence the next 2000 years. Borrowing and expanding from Pythagoreanism, it promotes the idea that everything in the universe moves in harmony and that the Sun, Moon, and planets move around Earth in perfect circles.

Aristotle, a Greek polymath, described motion of physical objects based on their affinity with one of four classical elements: earth, water, air, or fire.

The astronomer Shi Shen is believed to have cataloged 809 stars in 122 constellations, and he also made the earliest known observation of sunspots.