Perseus Brewster [Completed]

Chapter 9

"Ms,Tamadako. Paano po umiikot ang mundo sa araw?" Bigla nalang nag text saakin si Grace at hindi ko alam bakit automatic akong nag reply.

"Wait." Ng reply lang naman sya nang like.

"Our 8 planets, asteroids, comets, and some other solar system bodies revolve around the sun (or barycenter) in an orbit. Here in this article, you are going to learn about “rotation and revolution of planets around the sun“.

You can easily understand some important questions like, what causes these planets to revolve around the sun? Or how these planets revolve around the sun? Or Is there any fixed direction for revolution in the orbit? Just follow the article without skip to know about it.

Here we are going to discuss everything about the revolution of planets around the sun. But before understanding the revolution of planets, we should know how planets are formed and how they get initial velocity.

Our solar system including the sun, planets, and many asteroids all are formed around 4.5 billion years ago with the formation of the solar system. The solar system was formed due to the gravitational collapse of a giant cloud and dust in space. This made a disturbance in the cloud that results create clumps of gases due to gravity. Astronomers estimate that this happens because of the explosion with a supernova star.

Scientists believe that this interstellar cloud was so massive and started the contraction of the most molecules in the center. So the major part of this cloud and dust at the center made the Sun.

Other clumps of clouds and dust formed the planets and smaller bodies in the solar system, in which the majority of mass formed the planet Jupiter.

Why do planets revolve around the sun?

So due to the explosion and gravitational collapse of a giant cloud formed a system called the solar system in which our sun, 8 planets and their moons, dwarf planets and their moons, asteroids, and other bodies exist. Initially, these bodies have velocity due to the explosion in a certain direction.

Our 8 planets also got initial velocity in a certain direction. The gravity of the sun pulls these planets towards the center of the sun but the velocity of these planets is perpendicular to the force of the sun’s pull. This makes an equilibrium between the force of the sun’s gravitational pull and forces developed by the planet’s initial velocity.

The revolution of planets around the sun approximately follows Newton’s law of gravity but not totally. Whereas Einstein’s general relativity of theory gives an accurate calculation of the orbital revolution of planetary bodies.

According to Newton, gravity is a force and is the reason planets orbit the sun. When we drop any object it falls on earth due to gravitational pull. In the same way gravity of the sun pulls the planets. Sun is the heaviest object of our solar system so it develops the strongest gravitational pull.

Gravitational pull or centripetal force due to the sun, F= G×M1×M2/r2

Where G is the gravitational constant and its value is 6.67 × 10-11 Nm2/kg2

M1- the mass of the sun

M2- the mass of any planets

r – the distance between the sun and the planet

According to Einstein’s general relativity theory, gravity is due to curvature of the space-time. The heavier objects curve the space-time more compare to the lighter objects. The General Relativity Theory gives the highest accuracy to understand the orbital motion of the planets.

In this theory precession of the planets orbit and frame-dragging led the astronomers to a better understanding of the revolution of planets around the sun. Mercury has the most elliptical planetary orbit in our solar system and Newton’s gravity law was unable to explain it. While Einstein’s general relativity theory gives a precisely accurate result to understand the orbital path of even Mercury.