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A circle of twelve 30° divisions of celestial longitude that are centered upon the ecliptic. Ancient Babylonians are credited with creating the zodiac.

An astronomical event that occurs when the Moon passes between the Sun and Earth, and the Moon fully or partially blocks the Sun. This phenomenon was recorded and often feared in ancient civilizations like the Babylonians and the Chinese.

An apparent change in the movement of the planet through the sky. It is not real but rather an optical illusion. Studied by the Greeks, who provided significant contributions to the understanding of celestial mechanics.

Occurs twice a year when the Sun is exactly above the Equator and day and night are of equal length. Equinoxes were known to and celebrated by many ancient cultures, including the Mayans and the Egyptians.

The longest day of the year, when the Sun reaches its highest position in the sky. It was an important seasonal marker for many ancient cultures such as the Egyptians and Stonehenge builders.

The shortest day of the year, observed when the Sun is at its lowest daily maximum elevation in the sky. Celebrated and marked by many ancient cultures including the Stonehenge builders and the Romans with the festival of Saturnalia.

The first appearance of Sirius in the morning sky just before dawn. It was of great importance in ancient Egypt as it coincided with the annual flooding of the Nile River.

A short-period comet visible from Earth every 75-76 years. Known since ancient times, it was recorded by the Babylonians and is possibly depicted on the Bayeux Tapestry from medieval Europe.

The pre-dawn first sighting of the Pleiades cluster, which was used by ancient Greeks and the Mesoamerican civilizations to signify important calendar dates.