Where Does Perihelion Come from?

What is perihelion? The word comes from the Greek words peri (near) and helios (sun). It happens because Earth's orbit of the sun is slightly elliptical, so there are naturally two points during a complete orbit — one year — when it's closest and farthest away.

How does perihelion occur?

When the north pole is tilted away from the Sun, as it is now, the south pole is tilted toward it. As a result, summer is in full swing south of the equator even as northerners are bracing for a long winter. This morning at perihelion both hemispheres were 147.5 million km from the Sun.

What is perihelion and when does it occur?

Perihelion is the point of the Earth's orbit that is nearest to the Sun. Aphelion always happens in early July. About two weeks after the June solstice, Earth is farthest from the Sun. Perihelion always happens in early January.