We know that the Sun shows itself from the east during the day and moves to the west and is at its zenith at noon. When we end the subject with this, naturally, there is a perception that the Sun moves in a stable line throughout the year. But in fact, this issue is very different from what one might think.
Actually, the Sun moves forward in a year by drawing eight (8) signs. At the end of the year, the figure encountered upon completion of this drawing is called the Analemma. In order to see this situation, which most people are not aware of, we need to think more broadly and include two factors.
The first of these interconnected factors is the orbit of our planet around the Sun:
Earth, at certain times of the year It moves a bit faster as it gets closer to the Sun, and slower at other times. This is due to the fact that it follows an elliptical rather than circular orbit around the Sun. The breadth of the analemma is formed as a result of this movement. When the world accelerates, we see that a greater part emerges.
The second factor is axial tilt:
Let’s briefly explain what it is. The Earth has both an axis of rotation and an orbital axis as it revolves around the Sun. The angle between these two is called axial tilt. Since our Earth’s axial tilt is approximately 23.5 degrees, it rotates around itself in a slightly crooked manner, not perpendicularly as in the above image.
Thanks to this axial tilt, seasons change, days get longer and shorter, and the position that the Sun can reach in the sky changes over time. We’ve all heard of June 21 and December 21. These days, when the longest days begin in the Northern and Southern hemispheres, respectively, the Sun reaches the highest point it can reach and moves in the opposite direction.
So in the image you see below, the dots at the ends roughly correspond to these two days. Those in the northern hemisphere see the smaller part on top, while those in the southern hemisphere see the opposite:
Now let’s play with the terms a bit: Our orbit is rather elliptical What would the Analemma look like if it were circular?
In this case, if we turned the orbit into a perfect circle and left the axis tilt as it is, some of the eight figures in the sky would not be large while the other would not be small. Instead, they would both be of equal size.
Let’s say we left our orbit elliptical. What would Analemma be like if the axis had not been tilted, that is, if the Earth was not tilted but straight?
In this scenario, we would have said goodbye to the eight form altogether. Instead, the Sun would follow an elliptical path across the sky.
Finally, what would the Analemma look like if the Earth had no axial tilt and had a circular orbit around the Sun?
This scenario is the most boring. Because the position of the Sun at a certain time during the year would always be the same. So photographers who wanted to capture this moment couldn’t get more than one point at the end of the year.
So how is the situation on other planets:
- Mars
Analemma is due to the two factors we just mentioned, namely the orbital trajectory. depending on its shape and axial tilt. In other words, on planets where these two are in different combinations, different traces are formed from the shape of the eight we see from Earth. The movement of the Sun during the year on other planets is as follows:
- Mercury: 1 day equals 2 years, so single point
- Venus: Ellipse
- Earth: 8 or infinity sign
- Mars: Pena
- Jupiter: Ellipse
- Saturn: Teardrop
- Uranus: Eight
- Neptune: Eight
- Pluto: A gigantic eight
Analemma can also be formed by following the movements of the ‘Moon’ alongside the Sun
You can share your thoughts in the comment section.
Sources: Mathematical, Evolution Tree, Forbes, Love the Night Sky
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