why does the earth's lowest orbital velocity occur at aphelion?
Perihelion, Aphelion and the Solstices. The Earth is closest to the Sun â at its Perihelion â about 2 weeks after the December Solstice and farthest from the Sun â at its Aphelion â about 2 weeks after the June Solstice. Earth's orbit around the Sun changes. Earth is farthest from the Sun on its orbit when it is summer in the Northern Hemisphere.