Kepler's Laws of Planetary Motion

Johannes Kepler expounded the principles of Planetary Motion thus

1)The orbit of a planet is an ellipse, with the Sun as the focus of the ellipse.

3)The motion of a planet is fastest at Perihelion and slowest at Aphelion.

4) p1^2 / p2 ^2 = a1 ^ 3 /a2 ^3

The periods of revolutions ( sidereal period ) of two planets is equal to the cubes of their semi major axes.

Long before Kepler Aryabhata expounded the Helio centric Theory of Gravitation, that all planets circle around the Sun due to celestial gravity. If it is terrestrial gravity which is the characteristic of the earth, then it is Celestial Gravity, which is the characteristic of the Sun