Earth orbits the Sun at an average distance of 149. 60 million km (92. 96 million mi), and one complete orbit takes 365. 256 days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi). Earth's orbit has an eccentricity of 0. 0167. Since the Sun constitutes 99. 8% of the mass of the solar system, the center of the orbit is extremely close to the center of the Sun.