Perihelion and aphelion They are two terms that are commonly used in astronomy, but what exactly do they refer to and what is their relationship with our daily lives. They may not be part of the everyday vocabulary but they do have a great impact on planetary dynamics and therefore determine certain cycles of the Earth that are interesting to know.
Perihelion and aphelion
The translational movement of the Earth refers to the path that the planet travels around the Sun. This orbit is not perfect and on the contrary, it is elliptical, which means that there will be times when the planet is closer to the Sun and others where the most distant thing from it is placed. We know these points as perihelion and aphelion.
He term aphelion It comes from the Greek words ‘ἀπό’ which translates as ‘far from’ and ‘ἥλιος’ which means ‘Sun’, so it is a concept that refers to the points where a planet is as far away from the Sun as possible.
On the contrary, perihelion It comes from ‘περί’ which means ‘around’ or ‘around’, and ‘ἥλιος’ which we already saw means Sun. Perihelion is when a planet is at its closest point to the Sun.
Are the seasons due to perihelion and aphelion?
We often imagine the Earth moving around the Sun and rotating on its own axis in a very simple way. We have even added to the collective imagination that it is thanks to the fact that it pursues an elliptical orbit, which in certain months of the year is colder than in other periods due to the distance from the Sun. But in reality it is much more complex than this and no, the Seasons are not given by aphelion and perihelion.
Speaking of complicated issues about the behavior of the Earth, our planet not only has two movements, but at least five terrestrial movements are known and there are those who dare to say that it has many more. This is because it does not have a perfect circular orbit and is also inclined with respect to the ecliptic.
The ecliptic is an imaginary line that cuts horizontally across the entire Solar System, so it would be the line in which they move around the Sun. Having this as a base, we believe that the Earth is perfectly perpendicular to it (at 90º), but this is not true. Instead, It has an axis of inclination of 23.5º with respect to the perpendicular, thus land surface.
As it is not completely aligned at 90ºC on the ecliptic, the Earth does not always receive full sunlight, but there will be times when it tilts with the north pole more towards the Sun and it receives a greater amount of light. But the opposite will also happen, from the star and bringing the south pole much closer.
This movement is known as When the northern hemisphere tilts towards the Sun, it receives more solar energy and that is when we have summer in this region of the planet. But right at the same time the southern hemisphere is much further away and doesn’t receive as much light, so it experiences winter.
When will the perihelion and aphelion be in 2023?
The next perihelion will happen January 4, 2023 at 11:17 EST. During this moment the Earth will be placed 147 million kilometers from the Sun, which is more than 5 million kilometers closer than at aphelion.
He 2023 aphelion will occur during July 6, 2023 at 16:07 ESTa time when the northern hemisphere experiences summer and which contradictorily aligns with our planet at its furthest distance from the Sun at about 152 million kilometers.