Understanding Kepler’s Law is a guide used to study motion planet in outer space.
You may often wonder, how can a planet in space move on its axis?
Well, actually you can know this through Kepler’s Law. This law comes from the famous mathematician named Kepler.
Know the Definition of Kepler’s Laws to Understand the Planets
Planets that move around the Sun as its axis are common knowledge. However, did you know that it has a formula that can explain it?
Kepler’s laws are a guide for studying the motion of planets in space. Johannes Kepler was the first to put forward Kepler’s Laws.
Kepler was a German mathematician. Before Kepler’s Law, many people used to be geocentric.
Geocentric itself is an understanding that confirms that the Earth is the center of the universe. In other words, this ideology believes that the Sun and other planets pass through the Earth as an axis solar system.
Baca Juga: Persamaan Komet dan Planet Beserta Perbedaannya, Apa Saja?
In 1543, the Polish astronomer Nicolaus Copernicus proposed the heliocentric model which stated that all the planets revolve around the Sun, including the Earth. However, it cannot provide alignment between the trajectories and orbits of the planets.
It was only in 1609 that Kepler found a suitable orbit, which was an ellipse and not a circle. He explained it in Kepler’s three laws.
Kepler’s Law I
In terms of Kepler’s first law, it reads “The orbit of each planet when it revolves around the Sun is in the form of an ellipse and the Sun is located at one focus”.
This first law describes the shape of the orbits of the planets around the Sun. The shape of the elliptical orbit value is determined by the eccentricity (e) of the ellipse.
The greater the eccentricity, the thinner and longer the ellipse will be. Conversely, if the eccentricity is getting smaller, then the ellipse will be closer to the circle. The ellipse eccentricity value is greater than 0 or less than 1.
Kepler’s Second Law
Furthermore, there is the understanding of Kepler’s Law II which is a continuation of Kepler’s Law I. This second law explains that the orbital speed of each planet will depend on its distance from the Sun.
Planets that are at the farthest point of the Sun or aphelion will move slower. While the planets that are at the point closest to the Sun or perihelion move faster.
Baca Juga: Usia Tata Surya Kita Sama dengan Matahari? Berikut Penjelasannya!
In Kepler’s second law it reads “The line connecting the planet and the sun will always sweep the same area in the same time interval.”
Through this understanding of Kepler’s Law II, the conclusion we can draw is that the maximum orbital speed of a planet is when it is at its closest point to the Sun.
Likewise, the minimum orbital speed that will apply when the planet is at its furthest point from the Sun.
Kepler’s Law III
Understanding Kepler’s third law is the most recent. This law describes the period of revolution of the planets moving around the Sun.
The statement of Kepler’s Law is “The square of the period of a planet will be proportional to the cube of its average distance from the Sun”.
This third law explains that a planet has a longer orbital period when it is farther from the Sun. On the other hand, planets that are closer to the sun will have shorter orbital periods.
Baca Juga: Letusan Sistem Biner RS Ophiuchi Terlihat Mengeluarkan Sinar Gamma
Kepler’s Law Formulas
There are several formulas in understanding Kepler’s Law, which are as follows:
- Elliptical Orbit Area Formula
A = π ab
- A = speed of orbit (m2)
- a = the distance between the center point of the ellipse and the farthest orbit (m)
- b = distance between the center point of the ellipse and the nearest orbit (m)
- Average Speed Formula
ɳ = 2 π / P
- = average speed
- P = periode planet (revolusi)
- Kepler III’s Law Formula
(T1/T2)2 = (R1/R2)3
- T1 = Periode planet 1
- T2 = Periode planet 2
- R1 = Distance of the main planet from the sun
- R2 = Distance of the two planets from the Sun
Kepler’s Law formula has a function to calculate the trajectory of a planet or other celestial body that is also orbiting the Sun so that it can predict the time of its trajectory.
The concept of understanding Kepler’s Law is very useful for science astronomy. In addition, discussions about Kepler Law in Indonesia can also be found from high school materials. (R10 / HR-Online / Editor-Ndu)
–
