Astronomy

Eras

Olympiads – rendered as I Olympiad, II Olympiad, &c. – are 4 year intervals, so that II is 4 years after I.

The year has three beginnings: Spring (March), the Consulship (January), and the Indiction (September).

Seasons

Each season has two qualities: Autumn is dry and cold, Winter, wet and cold, Spring, wet and hot, and Summer, dry and hot. This corresponds to each element, earth is dry and cold, water, wet and cold, air, wet and hot, fire, dry and hot.

John of Damascus, St. “An Exact Exposition of the Orthodox Faith” in: The Fount of Knowledge.

Spheres

See the physics page for more about æther.

There are three heavens: the 1st, of air, the 2nd, of planets, and the 3rd, of stars. Each planet’s zone may be itself called a heaven.

Some conceive the world as semi-concentric spheres which are moved around each other, where east and west, and north and south, are intersecting circles. Some conceive the world as hemispheres instead, where east and west circle around north, south, then, the extremity from the center. Christians say either view is acceptable, but Greeks only accept the spherical view. At any rate, each planet is moved in an additional sphere of its own within their respective sphere/hemisphere.

John of Damascus, St. “An Exact Exposition of the Orthodox Faith” in: The Fount of Knowledge.

Ptolemy. Almagest.

Planets

Crosses were added to the planetary symbols in the 16th century.

The symbols for each are from Roman astronomy. Saturn’s and Jupiter’s are stylized initials – κρ and ζε, respectively – Mars’ is a spear & shield, Venus’, a hand-mirror, Mercury’s, a caduceus, the sun’s and moon’s, a solar beam and lunar crescent respectively.

John of Damascus, St. “An Exact Exposition of the Orthodox Faith” in: The Fount of Knowledge.

Zodia

Note: Each of the 12 zodia has 30 degrees, 10 for each decan, thus totalling 360. Man, correspondingly, has two sets of 12 ribs, and 360 joints.

John of Damascus, St. “An Exact Exposition of the Orthodox Faith” in: The Fount of Knowledge.

Constellations

All the ancients were in harmony regarding the number of constellations – 48, no more nor less. There was disagreement regarding what those were, but not how many.

The Ægyptians called the 36 non-zodiac constellations decans – meaning ten – because each marked the passage of 10 days. The Persians divided the constellations into 12 groups of 4 – 1 zodiac with 3 decans. An additional 5, now 5 1/4, days were added for a total of 365 days in the year. Thus, the decans told the days, and the zodia, the months.

The Persians distinguished a constellation called the bands from the fishes, and did not recognize the horse. Some Greeks did not distinguish the scales from the scorpion.

• Northern Ecliptic

• Northen Zodia

• Southern Zodia

• Southern Ecliptic

The first number is the count of stars in the constellation, the second, the count of unfigured stars, i.e., those not part of a constellation.

Many so-called constellations that are contemporaneously known are parts of these. E.g., the “southern cross” is the centaur’s right hindleg.

Ptolemy. Almagest.