On July 5, the Earth will pass through its furthest point from the Sun in its orbit in 2024. It is an astronomical milestone known as aphelion. The phenomenon occurs every year between July 2 and 7, when the Earth reaches its minimum speed.
The exact moment of greatest separation will occur at 00:06 UTC. This is when the Earth and the Sun will be 152,098,455 kilometers apart. This is about five million kilometers further than at perihelion, which this year occurred on January 2, according to the US Naval Observatory.
Kepler’s law
The Earth orbits the Sun in an elliptical orbit of 930 million kilometres, at an average speed of 107,280 kilometres per hour. This means that it covers the distance in 365 days and almost 6 hours. This is why every four years is counted as a leap year.
But, according to Kepler’s second law, this speed of translation varies. It increases to a maximum at perihelion (the shortest distance from the Sun) at 110,700 kilometres per hour. And it decreases to a minimum at aphelion, at 103,536 kilometres per hour. That’s more than 7,000 kilometres per hour difference. That’s when the Earth reaches its minimum speed.
A question of distances
Kepler realized that the line connecting the planets and the Sun covers the same area in the same amount of time. This means that when the planets are close to the Sun in their orbit, they move faster than when they are farther away.
Thus, the orbital speed of a planet will be lower the greater its distance from the Sun. And at shorter distances the orbital speed will be higher. The average distance from the Sun is 150 million kilometers. At aphelion it reaches 152.09 million kilometers and at perihelion it drops to 147.10 million kilometers.
