when does earth move fastest in its orbit?
On January 3, 2011, when the Earth was at its closest to the Sun (perihelion, 147.1 million kilometers), it was traveling at 30.29 km/s. On July 4, 2011, when the Earth was farthest from the Sun (aphelion, 152.1 million kilometers) it was traveling at 30.29 km/s.