Why do almost all planets have a spherical appearance?

As far as the solar system is concerned, the celestial bodies of the solar system are born with the birth of the sun. At the beginning of the formation of the sun, due to the gravitational force, the nebula will slowly shrink towards the center and form a vortex, when the stellar disk composed of a huge molecular cloud continues to rotate in the center, the mass and gravitational force of the original star will increase more and more, the inner center is centered on the center of mass, and the gravitational force in all directions is equal, that is, the force is balanced, thus forming a sphere. When the primordial sun reached a certain level, the interior was compressed to tens of millions of degrees, and nuclear fusion occurred, forming stars.

To be correct, not all planets are round! There are nebulae, asteroids, and moons that are not spherical in shape, but in an irregular shape. Of course, most of the planets we see are round.

The remaining nebula dust material will inherit the angular momentum and continue to rotate, and while rotating, it will also be attracted and gathered due to the action of gravity, and the collision and fusion will occur with each other at the same time, and over time, the collision and fusion will cause the mass to increase more and more, and the high temperature generated by the previous collision will liquefy these dust fragments, thus becoming a lava planet.

When the mass of the planet is large, the internal gravity will produce gravitational potential energy, resulting in the surface potential energy of the celestial body will reach equilibrium only when it tends to be spherical, and then the lava planet gradually cools down, forming a rocky planet like the earth, and the nebula gas accumulation forms a gaseous planet, so why are the celestial bodies that reach a certain mass round.

Because the force of the gravitational field originates from the center of the star, it pulls all the matter inward; The massive body of the planet, combined with the heat generated by the radioactive elements inside, behaves like a liquid, succumbing to the gravitational pull from the center of gravity for a long time, thus forming a circle. The only way to get all the matter as close to the planet's gravity center as possible is to form a sphere; This process is called equalization.

Naturally, there is no solid, liquid state of matter on the star, but it is all in the state of gas. The gas diffusion is the same in all directions, and the extent is roughly the same, and all parts of the gas are controlled by gravity. So when these forces are balanced, it must be a ball in appearance.

Because the planet needs to rotate, it is spherical.

The interaction of the centroid and mass gives all planets a spherical appearance.

Because it is good for rotation, revolution, floating.

The oblate sphere shape is the result of two main factors: gravity and rotation. All objects with mass, the gravitational force of which tries to crush the object inward through all directions.

Because the rules of physics do not allow for other shapes.

Not round but spherical. For a celestial body with a similar composition to the Earth, when its own mass is greater than 1e21 kg, its own gravitational pull is enough to overcome the structural strength of its own material and tend to be spherical

The planet's massive body, combined with the heat generated by the radioactive elements inside, behaves like a liquid.

All conventional substances, including solids, exhibit both plastic and fluid substances, on sufficiently long time scales.

Because of the isotropic nature of gravitation.

1. The reason why these substances that form celestial bodies can be gathered together is because there is gravitational force, and the gravitational force acts in the same direction (i.e., the so-called isotropy in physics), so it must form a sphere. Like the electric field around a point charge, since this electric field is isotropic, its equipotential surface is spherical.

2. Any celestial body with a large head (a hall size is at least equivalent to a planet, excluding nebulae) is approximate to a sphere. Smaller celestial bodies such as asteroids, comets, etc., have less gravitational attraction and are therefore farther away from the sphere.

3. The uneven existence of the internal forces of the celestial bodies and the forces between the celestial bodies will cause the surface of the sphere to fluctuate, such as the mountains, river valleys, tidal activities on the earth, and the violent activities on the surface of the sun. Hidden.

4. The rotation of a globular body causes its equator to bulge slightly.

5. Some people use the analogy of water droplets, but in fact there is no comparison. Even spherical water droplets are formed on a completely different basis except for their resemblance to spherical objects, so most water droplets (such as raindrops) are not spheres.

6. There are still people who talk about surface tension, and they are completely laymen.

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The Sun is a star located at the center of the solar system, and it is almost an ideal sphere intertwined with hot plasma and magnetic fields. The diameter of the Sun is about 1,392,000 (kilometers, equivalent to 109 times the diameter of the Earth; It is about 1.3 million times the size of the Earth; Its mass is about 2 10 kilograms (330,000 times that of the Earth).

In terms of chemical composition, about three-quarters of the mass of the Sun is now hydrogen, and almost all of the rest is helium, including oxygen, carbon, neon, iron, and other heavy elements with less than 2% of the mass, which uses nuclear fusion to release light and heat into space.

3. From the current scientific point of view, the reason why most of the stars in the rain are spherical may be that they have been set up as a system, and they need to be further explored and discovered by human beings. In fact, for us, many people are doubting that the crystals in the oil are refined, in some ways, this seems to be a quote guideline, but it may be that someone deliberately set the same operation, so it is more necessary for human beings to continue to progress, explore and discover, and hold people to better understand the unknown universe.

The spherical shape in the universe may reach a kind of gravitational equilibrium, and in some ways, spherical stars are more conducive to the stability of the universe, but it seems that the setting of the spherical stars is like this, so it is more necessary for human beings to further develop to explore the universe in this position.

Causes of gravity and rotation. All objects have a self-gravitational pull and compress from the middle of the quadrangle, which, combined with the rotation of the stars themselves, is why stars are mostly oblate spheres.

Because the stars have a gravitational pull, they will attract objects on the planet to move closer to the center, so they are all spherical.

Because the spherical planet runs more smoothly, it can maintain the relative stability of the universe to the greatest extent.

Because the matter on the stars is gravitationally attracted and gathers towards the center, most stars are spherical. Because some asteroids are small enough to gravitate enough to change shape, not all matter exists as spheres.

In general, the reason why most of the relatives in the universe are stars may be because of the rules of the universe, in some ways, spherical objects are better suited to survive in the rain, and in most cases, if they get rid of the spherical shape, then due to gravity, the object will also appear as a broken star, so it is said that the star is better to establish equilibrium and can maintain the state of a planet. In general, there are several reasons.

All matter has a central point, and the only way to get close to it is to be spherical. Not all matter exists in a spherical shape.

Answer to question1:

This is true of the Earth and the eight planets.

First, the circle is the most stable and perfect shape. Planets, especially large ones, must be round in order to maintain their own balance;

Second, the influence of gravitational force. There will be a lot of matter on the planet, in order to ensure that these substances do not fly out, these substances have to be pulled into the center of the planet, which is the gravitational force, under the action of gravity, the planet will become circular over time;

Third, the movement of the stars in the air is mainly revolution and rotation, and the raised corner will be thrown away in the process of rotation, and the stars will slowly become round;

Fourth, the star is formed by absorbing tiny particles in rotation, and the small star rotates around the large star, and finally is swallowed up by the large celestial body, and so on, and finally becomes a large circular star.

That's when you don't see asteroids in space, many asteroids are irregularly shaped, some comets made of ice and dust are also irregular in shape, and some binary galaxies are elliptical because of the gravitational influence of each other.

This is called "nature", the creation of celestial bodies.

Maybe the reader is your teacher.

In fact, the reason why these planets are round is because the force of the gravitational field comes from the center of the star, pulling all the matter inward; The huge body of the planet, combined with the heat generated by the radioactive elements inside, behaves like a liquid state, succumbing from the center of gravity to the action of gravity for a long time, thus forming a circle. The only way to get all matter as close as possible to the Earth's center of gravity is to form a ball, a process called equilibrium adjustment, but not all planets are round.

For example, for smaller stars, the asteroid's gravity is too small to exceed the strength of its own structure. Thus, these stars also maintain an irregular and incomplete shape and do not form a spherical shape because the planets are rotating and due to centrifugal force, the planets will become stable shapes in all directions. In three-dimensional space, only spheres match, so it is a sphere, and in general, as long as the diameter of the planet is more than 400 km, the probability of 99 will be spherical.

These planets with a certain level of volume and mass are enough to produce large amounts of lava inside the planets, however, lava activity in the Earth's interior will keep all parts of the Earth under uniform force. Places that are too high will collapse and become shorter, while places that are too short will be pushed higher by internal forces, so the planet will gradually become spherical. Of course, the planet is subject to rotation and revolution, as well as other planetary gravity.

Its shape doesn't have to be standard spherical.

Just like the Earth, it's not a very standard spherical shape either. It can be said that it is not easy to find a standard spherical planet in the universe. Most of the planets are not standard spherical in shape.

So is there a planet in the universe that is not spherical? The answer is that it exists, and although such planets are relatively rare, they do. However, there is such a dwarf planet in our solar system.

Of course, it's not Pluto.

As for the question of why the planets are all sphere-shaped, and there are no other shapes, this is explained today.

Because the objects on the planet will move closer to the center due to gravity, they are all spherical. Of course, there are also some very small asteroids that will have some irregular shapes.

Not all of them are spherical, only the larger and more massive planets are mostly spherical, there are other shapes of planets, and many asteroids are quadrilateral or irregular because of their small size.

Because the power of the stars pulls all matter inward. It's not that there are no other shapes, some planets are elongated. But the number is relatively small.

Stellar: The most typical is the Sun, where the maximum temperature on the surface of the star can reach 40,000 to 70,000, and the lowest is also in the thousands of degrees Celsius. In this case, there is no solid, liquid matter on the star, but some gaseous state.

The gas diffusion is the same in all directions, and the range is roughly equal, and the gas in all parts is controlled by gravity. So when these forces are balanced, it has a spherical appearance, which is one reason why the stars we look like are round.

Planet: It does not emit light per se, it is not a star in a gaseous state, but a hard solid sphere. But when it was just taking shape, it was also a red-hot molten substance.

Because it has a rotation, it changes its shape to be spherical or oblate. The spherical shape thus formed is mechanically called a "rotating sphere", or "rotating ellipsoid". The moons of the Moon and some other planets are also round and oblate in shape.

Of course, in the universe, in addition to stars and planets, there are also some nebulae, asteroids, moons and other celestial bodies, these celestial bodies are not spherical, but show an irregular shape, but because the number of these celestial bodies is not large, most of our planets are round.

We all know that the reason why the planet is round is because the force of the gravitational field originates from the center of the star, pulling all the matter inward. The massive body of the planet, combined with the heat generated by the radioactive elements inside, behaves like a liquid, succumbing to the gravitational pull from the center of gravity for a long time, thus forming a circle. The only way to get all the matter as close to the planet's gravity center as possible is to form a sphere; This process is called isostatic adjustment.

But not all the planets are round.

For smaller stars, such as asteroids, the gravitational force of the asteroid is too small to exceed the force of its own structure. Therefore, these stars also retain the irregular and incomplete shape of Hengnabu, and do not form a spherical shape, because the planets are rotating, because of the centrifugal force, the planet becomes a shape that is stable on all sides. In three-dimensional space, only spheres match, so it's spheres!