Major Astronomical Observations known to ancients:

The ancients had no telescopes but they were aware of many astronomical phenomena that are observable with the naked eye.

• The sphericity of the Earth.

• The visibility of different constellations at difference latitudes on Earth and the circumpolarity of some stars.

• The confinement of the motion of the Sun, Moon and planets to a band around the ecliptic.

• Rapid diurnal westward motion of the Sun with respect to the stars.

• Slow annual eastward drift of the Sun along the ecliptic with respect to the stars.

• The phases of the Moon, and their correlation with the time of moonrise and moonset.

• The occurrence of eclipses, both solar and lunar.

• The differences in motion of the inferior and superior planets.

• The retrograde motion of the planets and the variation in the speed a planet moves around the sky.

What causes these phenomena?

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