Again, I refer you to Kepler's 3 laws which follow from Newton's laws. Why they are true starts getting outside the realm of science and into metaphysics.

Dr Neal Hulkower thank you for your contribution to the discussion

Kepler's Second Law Describes the Way an Object's Speed Varies along Its Orbit. A planet's orbital speed changes, depending on how far it is from the Sun. The closer a planet is to the Sun, the stronger the Sun's gravitational pull on it, and the faster the planet moves. It is observed that as the planet gets closer to the sun, the planets move faster because the gravitational pull from the sun gets stronger. Also, the moment of inertia about the axis decreases for all the planets. Angular velocity increases to conserve angular momentum. The line joining a planet to the Sun sweeps out equal areas in equal interval of time. The rate of change of area with time will be constant. We can see in the above figure, the Sun is located at the focus and the planets revolve around the Sun. That is the aerial velocity of the planets remains constant. For the planets, as they go around the Sun, their masses don't change but their distances from the Sun do. As they get closer to the Sun they orbit faster. The product of these two quantities remains unchanged, thus angular momentum is conserved. Earth is moving round the sun without slowing down because the gravitational force of sun pulls the earth always in same force. The sun and the solar system appear to be moving at 200 kilometers per second, or at an average speed of 448,000 mph (720,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way. Also, the angular velocity of the revolution of the planets around the sun increases and this can be explained using Kepler's second law. It is observed that as the planet gets closer to the sun, the planets move faster because the gravitational pull from the sun gets stronger.