Do all planets in Milky Way have an oval orbit?

1 Answer
Jan 17, 2016

No.

Explanation:

"Oval" is a rather vague term literally meaning "egg shaped", that is some kind of elongated circle.

To be more precise, the word you probably need is "elliptical" rather than "oval". Ovals have various different definitions and are not normally elliptical.

Secondly, though it is in theory possible for the orbit of a planet around a star to be circular, there will always be some eccentricity, so it will be closer to an ellipse.

Thirdly, planets are often not alone in orbiting around a star. If there is more than one planet (or indeed star) then they will perturb one another's orbits. So they will not be perfect ellipses.

Fourthly there are estimated to be billions of "rogue" planets in the Milky Way, not orbiting any particular star.