How do aphelion and perihelion compare to one another?

The point in a planet's orbit where it is furthest from its star is known as its apothelion.

The point in an orbit where a planet is closest to its star is called its perihelion.

Let's use Earth as an example.

Because Earth's orbit around the Sun is an ellipse rather than a perfect circle, the average distance between Earth and the Sun is approximately 149 million km.

With a perihelion distance of roughly 146 million km, the Earth's aphelion distance is approximately 152 million km.

If you know the average distance, or Semi-Major axis, between an object and the sun, as well as the eccentricity of the object's orbit, you can compute the perihelion and apohelion of any object.

The following formulas make it simple to calculate aphelion and perihelion distances.

Phaenomenon = a(1 + e)

A (one - e) is the perihelion.

Whereas

The average distance, or semi-major axis, between the star and the object is denoted by a.

e is the orbit's eccentricity.

This can be calculated as in the case of Earth.

Aphelion is the point in a planet's orbit where it is farthest from the Sun, while perihelion is the point where it is closest to the Sun.