why is that all planets are round in shape?

Answer 1

Because any point of the surface of a sphere is equal distant from the center of the planet. That is due to the force of gravity being equal in all dimensions, pulling the surface down with equal force at all points on the surface.

That said, enormous tectonic forces can force up mountains and force down valleys on an otherwise smooth surface.

Answer 2

All of the planets are round because of gravity. When our solar system was forming, gravity gathered billions of pieces of gas and dust into clumps which grew larger and larger to become the planets. The force of the collision of these pieces caused the newly forming planets to become hot and molten. The force of gravity, pulled this molten material inwards towards the planet's center into the shape of a sphere. Later, when the planets cooled, they stayed spherical. Planets are not perfectly spherical because they also spin. The spinning force acts against gravity and causes many planets to bulge out more around their equators.

Answer 3

The larger the object, the stronger its gravitational field.

If a planet was like a cube, the corners of the cube would be higher than the rest of the planet. Since planets and stars are so big, you cannot build a "foundation" strong enough to hold up those corners! Anything you built it out of would be too weak to hold them up. Gravity would eventually pull them down.

Gravity pulls toward the center of the planet or star, everything gets pulled down into a sphere. However, planets and stars are not really perfect spheres.

Answer 4

Liquid forms a sphere in micorgravity. Bevcause planets are in free fall around the sun and at early stages were all liquid they took the form of balls. Tidal forces to make them buldge. Jupiter spins so fast that it is only 96% spherical...in the middle it is a littl fatter. The Kuipter belt objects such as pluto were at one point closer to the sun then they are now and got "pushed out" to a farther orbit when Neptune formed. When they were closer to the sun they were liquid and spheres when they got pushed out they froze into solid ball like shapes

Answer 5

I think gravity holds the answer.
At the early stages all the planets were made up of liquid and gas.
Two forces acts on any celestial body : - 1. Pressure.
2. gravity.
the force of gravity is inversely proportional to the distance of the object from the centre of the mass as per the Newton's law of gravitation i.e.
F=GM1M2/R^2
consider any elemental fluid mass situated at a distance of 'r' from the centre of mass. The force acting on it will be
f=Gm/r^2
If we consider this fluid element in the hydrostatic equilibrium then the hydrostatic force should balance the gravity force and then the element will remain at its place.
Hence a planet to remain in equilibrium its fluid elements must remain at a distance of 'r' from the centre of mass which will form one hollow sphere of radius 'r'. Such other layers will be formed giving a sphere.

Answer 6

Planets (...and also stars) form within immense drifting clouds of gas and dust. Every bit of gas and dust generates a tiny gravitational force. In relatively dense regions of the drifting cloud (...called a 'nebula') two or more bits of gas or dust may be close enough so that they're attracted to each other by their gravity. They clump together, which increases their overall gravity. This larger clump is surrounded by more bits and pieces which are drawn in from all directions. The original clump grows in size and produces more gravity, which in turn pulls in even more material from all directions. The result is a growing sphere.

Answer 7

Apart from the gravity concept, they are round also because that is the shape which is suited the best for Minimum Friction during rotation

Answer 8

Planets are not perfectly round, (our moon has a bump on it but looks round)
Gravity, heat, inpacts and lots and lots of time will attempt to make these bodies round.

Answer 9

Gravity pulls matter equally in all directions giving heavenly bodies a near spherical shape.

Answer 10

well first of all most planets have a molten core. so when they begin to spin they will form a ball. take a glass of water and let one drop out and watch what happens. it will form a teardrop shape and as it falls if you can slow it down it will also form a ball shape.well molten rock or metal when spun will do the same thing.