Have you ever thrown an apple? Where did the apple fall? Certainly the answer is falling down. Now the question is, why is that? Is it due to the rotation of the earth? Because of the earth revolution? Or because of earth precession? Unfortunately not all three. Apples that are thrown will fall to earth because of the earth’s gravitational force.
Is Earth’s gravity a kind of earth motion? No. Earth’s gravity is the attraction of the earth in attracting other objects to go to the earth. Whatever it is. Well, the earth’s gravitational force also causes the earth’s satellites, namely the moon, around the earth. Now, however, why does this force not make the moon not fall to earth?
To understand this, we can go deeper into Newton’s theory of gravity. This theory is the basis of understanding that is used to explain the motion of objects in space in the solar system and also at the same time become the basis for the motion of aircraft between space.
So that you are not confused, you must know first that this time, we will discuss about the Kinds of Earth’s Movement. This earth movement consists of Earth Rotation, Earth Revolution and Earth Precession.
There are two planets of the solar system that we know and study, namely the rotation of the earth and revolution. Earth’s rotation is the motion of the earth that rotates on its axis, while the earth’s revolution is the movement of planets that circulate around the sun.
Some form of planetary motion around the sun can be seen from certain characteristics, which include:
- The planet’s orbit is almost circular in shape (small eccentricity). The planet that has the greatest eccentricity is Planet Pluto, i.e. e = 0.249.
- Orbit all the planets close to one.
- All the planets around the sun are in the same direction.
Regarding the motion of the planet, Johanes Kepler (1571 – 1630) found 3 laws of planetary motion, namely Kepler I law, Kepler II law and Kepler III law. Regarding information regarding Kepler’s law, please read the three laws in the Kepler Law article I, II, and III .
Now, next, we will discuss the types of earth movements which are divided into 3 namely rotation, revolution and precession. The following explanation.
Chapter List ☰
Earth’s rotation is a movement in which the earth rotates on its axis. In the rotation process, each time the earth’s rotation takes 23 hours 56 minutes 48 seconds or normally rounded to 24 hours for 1 period. The rotation time of the earth is what is commonly referred to as a day.
The direction of rotation of the earth itself goes from west to east. Because of this movement, celestial bodies seem to move from east to west. We can observe this by watching the sunrise starting from the east and then moving and sinking to the west.
More can be seen in the article about the effects of earth rotation .
The earth revolution is a movement of the earth around the sun. In one revolutionary period, the time needed is 365¼ days or commonly referred to as 1 year. Earth made a revolution can be known by the proof of the phenomenon of stars in the sky that seem to move places, and with a trajectory that resembles the path of the earth around the sun.
For more information about this revolution, it can be seen in the article due to the earth revolution .
In addition to rotation and revolution, there is another motion of the earth, namely precession. Earth precession is indeed discussed less frequently than rotation and revolution. But this movement is also important to know and learn.
The meaning of precession itself is the motion of the earth’s rotating axis. Where the earth’s rotating axis (KU – KS) does not always lead to the same point in the sky, but rotates like a spinning top.
Precession movements occur very slowly. For one precession period, the time needed is 26,000 years. So, from this movement, then in the 20th century, the north celestial pole will be near the Polaris star, and in 12,000 years, KU will be near the Vega star.
So, that is the explanation of the Kinds of Earth’s Movement: Earth Rotation, Earth Revolution and Precession . It’s clear right? Hopefully this article is useful.