What is perihelion? Explains the meaning of the term and when the Earth will be closest to the Sun in 2023.

Today, the Earth is closest to the Sun, a phenomenon known as “perihelion.”

Perihelion always occurs in early January, but not necessarily on the same day, as the calendar year does not exactly match the time it takes the Earth to orbit the Sun. The term and its meaning are explained here.

What does perihelion mean?

Perihelion comes from the Latin prefix Perimeans near, and the Greek word for the sun is helios. The term refers to the point in the orbit of a planet or other astronomical body where it is closest to the Sun.

The opposite is “Aphelios”, which uses a Latin prefix meaning “away from”.

The Earth, like other planets in the solar system, revolves around the sun in an ellipse. However, the Sun is not entirely at the center of these ellipses, instead it follows its own small elliptical orbit around the solar system’s center of mass, known as the centroid.

The center of gravity is not exactly in the middle of the planet’s elliptical orbit, which means that there will be a point in the year when this planet is closest to the Sun.

Space. com explains: “If you draw a line through the center of mass to connect the farthest points of the orbit of a smaller body, part of the line will lengthen (apse) and part will decrease (periapsis). The point at which the periapsis intersects the body’s orbit is called the perihelion, the closest point of the body’s orbit to the Sun.

How close is the Earth to the Sun?

At perihelion, the Earth is 91,403,034 miles from the Sun. This compares to a distance of 94,506,364 miles at aphelion on July 6, 2023.

This means that the difference in distance from the Earth to the Sun at perihelion and aphelion is about three million miles.

The distance between the Earth and the Sun does not affect the seasons, but is determined by the tilt of the earth’s axis. So, unfortunately, perihelion does not mean a day or warmer and clearer weather.