Why planets choose ellipse path to revolve sun instead of round?

Question

Why planets choose ellipse path to revolve sun instead of round?

Answer 1

A perfectly round orbit isn't possible. For one thing a planet doesn't just orbit a star. They orbit each other around a common point. Even disregarding that, a circular orbit wouldn't be stable. The tiniest influence would change it to an elliptical orbit.

Answer 2

Planets don't choose their orbits. Orbits are determined by the momentum of the planet at time of capture by the host planet.  Their orbits tend to round out over billions of years but physics being what it is, there is no way for them to be perfectly round.

Answer 3

In order to orbit in a circle, a planet would need to maintain an exactly constant distance from the Sun and constant speed in its orbit. The slightest deviation from this would mean that the orbit was no longer a circle. The theory of the evolution of the solar system says that it gradually settled down from an initially chaotic state to the present reasonably well-ordered system with the major planets suitably well-spaced from one another. However, the chances of all the orbits settling down to exact circles is vanishingly small. Even if the planets could be placed in exactly circular orbits, their gravitational pull on one another would soon cause their paths to deviate from circles.

Answer 4

planets orbits are all ellipical,and are governed by the laws of gravitation which are far to complicated to explain here.In any case a circle is just a very special ellipse