Observing, interpreting and understanding celestial bodies and their movement in space like the galaxies and constellations, were not easy in the ancient era, but astronomers of those times still tried to discover what was out there. Their efforts were not in vain. Early astronomers were among those who actually recognised the power of mathematics in explaining nature. It was a great discovery for the scientific world, that the motions of the Earth and other celestial objects in space could be explained by the laws of mathematics.