The eccentricity of Earth's orbit is currently about 0.0167; its orbit is nearly circular. Venus and Neptune have even lower eccentricities. Over hundreds of thousands of years, the eccentricity of the Earth's orbit varies from nearly 0.0034 to almost 0.058 as a result of gravitational attractions among the planets.

Does Earth have the most eccentric orbit?

A perfectly circular orbit has an eccentricity of zero; higher numbers indicate more elliptical orbits. Neptune, Venus, and Earth are the planets in our solar system with the least eccentric orbits. Pluto and Mercury are the planets in our solar system with the most eccentric orbits.

Is Earth's orbit an eccentric ellipse?

The orbit is slightly elongated into something more eccentric (termed an ellipse) than a perfect circle. At times the Earth is closer to the Sun that at others (Fig. 7.23). The orbital variation is not as extreme as depicted in this picture, but it is something other than a circle.