Mithras - Lord of Ages

Astronomical Matters

Plane of the Ecliptic and Plane of the Celestial Equator

The above diagram depicts the Celestial Equator and the Circle of the Ecliptic on the Celestial Sphere. The spectator on Earth sees the heavens rotating in twenty-four hours around the North-South Polar Axis. To an observer on Earth, the motions of the Sun, Moon and planets occur only within this Band of the Ecliptic, inclined at an angle of 23½ degrees above and below the Celestial Equator. The constellations of fixed stars that appear within the Band of the Ecliptic are called the Zodiac. The Zodiac has been arbitrarily divided into twelve zones, each zone encompassing one constellation of the Zodiac. The two circles, equator and ecliptic, meet at the equinoctial points. They are widest apart from each other at the solstices. The inclination of the ecliptic causes the observed path of the Sun to appear to swing up and down according to the seasons: in the Northern Hemisphere, it is highest at the summer solstice, lowest in the winter solstice. Therefore, to someone on earth, the motion of the Sun in the sky, will appear to describe throughout the year, a spiral up and down movement between the two solstitial latitudes, the Tropic of Cancer north of the Equator and the Tropic of Capricorn south of the Equator (the Torrid Zone); and so, of course, will the motions of the Moon and planets. It is very important to note that the circle of the Ecliptic (the Solar Equator) and the circle of the Earth's Equator intersect each other at an angle of 23½ degrees. This intersection creates a kind of a huge "X" mark or "Cross" in the sky. This "cross" was of huge importance to the Pythagoreans and the Platonists. I shall revisit this phenomenon when I discuss the writings of Plato in the Timeaus, et al. For the ancient philosophers and astronomers to be able to visualize these separate circles of the Equator and Ecliptic in the sky was a feat of considerable intellectual abstraction.

Pertinent Constellations

Precession of the Equinoxes