Answer: 1) every planet’s orbit is an ellipse with the Sun at a focus. 2) a line joining the Sun and a planet sweeps out equal areas in equal times. 3) the square of a planet’s orbital period is proportional to the cube of the semi-major axis of its orbit. Log in to Reply

Answer:1) every planet’s orbit is an ellipse with the Sun at a focus.

2) a line joining the Sun and a planet sweeps out equal areas in equal times.

3) the square of a planet’s orbital period is proportional to the cube of the semi-major axis of its orbit.