At the beginning of July, the Earth will reach its farthest point from the Sun, known as aphelion, at a maximum distance of about 152 million kilometers from the central star of our Solar System.
When is the aphelion in 2023?
The Earth reaches its maximum distance from the Sun on July 6th at 20:08 UTC.
In 2023, the aphelion will occur on July 6th at 20:08 UTC. This phenomenon, which occurs every year, fascinates and raises many questions. Here we explain why it happens and what consequences it will have.
The Earth reaches its maximum distance from the Sun
The Earth orbits around the Sun in a trajectory that lasts 365 days, covering an elliptical orbit. The hypothesis that the orbits of the planets were elliptical was formulated by the German astronomer Kepler, a contemporary of Galileo Galilei.
The fact that the Earth’s orbit around the Sun has an elliptical shape, rather than a circle, has obvious consequences: there is a time of the year when the Earth is farthest from the Sun and another when it is closest. The point of closest proximity is called perihelion and is reached in early January when the Earth reaches a minimum distance of 147 million kilometers from the Sun.
The point of maximum distance is called aphelion, a term introduced by the astronomer Kepler, who used the Greek words “apo,” meaning “away from,” and “helios,” meaning “Sun.” This moment is reached in early July when the Earth is about 152 million kilometers away from the Sun.
Farther from the Sun in the middle of summer: How is this possible?
It may seem strange, but the succession of seasons is not linked to the distance between the Earth and the Sun. The difference between 147 and 152 million kilometers does not influence the succession of seasons and is imperceptible to us humans.
Therefore, this explains why, even though the aphelion occurs in early July, it is midsummer in the northern hemisphere. In the southern hemisphere, remember, it is currently winter, which further supports this thesis.
The succession of seasons is not linked to the distance between the Earth and the Sun, which, as we mentioned, does not vary enough to affect the warming of the planet. Instead, it is due to the tilt of our planet with respect to the Sun’s rays.
Our planet completes its elliptical orbit around the Sun tilted about 23° with respect to the perpendicular to the plane of its orbit. Throughout the year, the particular inclination of the Earth causes different regions of the planet to be reached by the Sun’s rays in different ways.
During summer in the northern hemisphere, the Sun’s rays reach the northern hemisphere with less inclination and for a longer time, while the opposite occurs in the southern hemisphere. This determines the alternation of seasons and the occurrence of important astronomical moments such as equinoxes and solstices.