Are the solar system orbits circular?

Answer 1

There are no solar system orbits that are perfectly circular, because all have at least a slight change in orbital distance as they circle the Sun (eccentricity). For Mercury and Pluto, the different between the closest and farthest points is fairly large, while for Earth it is much smaller.

Answer 2

The orbits of many, but not all, artificial Earth satellites are nearly circular. They are generally that way by design, that is the engineers who designed the orbit specified the parameters and the required rocket motor burns needed to achieve the orbit as designed. A few satellites are designed to have highly elliptical orbits so that they spend more time over one part of the Earth than another. These are often non-geosynchronous communications satellites, but could be reconnaissance satellites. Satellites with near circular orbits are designed that way based on the desired orbital altitude required to support their mission, for example how much of the Earth to see at one time, or how close to the Earth's surface for imaging or minimum communications delays. Orbits of low Earth orbit satellites are also circularized to minimize drag in the Earth's atmosphere, that is to avoid low perigees. If you were asking about natural satellites such as the Earth's moon, leave a note on the discussion page and I or someone else will try to help.

Answer 3

No, the orbits of planets in our solar system are not perfectly circular but are slightly elliptical. This means that the shape of the orbit is more like an oval than a perfect circle.

Answer 4

No. All orbits are elliptical.