Aphelion is the point in the orbit of a planet, asteroid, or comet where it is farthest from the Sun. For Earth, this occurs in early July. The concept of aphelion is important in understanding the variations in solar energy received by a planet, which can influence seasonal climate patterns. The difference in distance between aphelion and perihelion (the closest point) contributes to the Earth’s elliptical orbit.
Source Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., & Levrard, B. (2004). “A Long-Term Numerical Solution for the Insolation Quantities of the Earth.” Astronomy & Astrophysics, 428(1), 261-285.