Why are all planets spherical in shape?

Question

I don't see a square one around.

Answer 1

if you can picture a gyro spinning, picture it spinning out of control. or take a quarter and drop it on a table and watch it before it stops moving. it's all about speed. the rate of inertial is so grate the human eye can not see and regulate it at the same time.

Answer 2

According to current astronomical theory on the formation of planets, the solar system started out as a solar nebula made up of gas and dust. The planets formed from collisions of material in the solar nebula. At first, the particles were small, and sometimes collisions caused them to stick together forming larger and larger "planetisimals". As the objects became larger, gravity began to play a role in attracting other particles so that they continued to grow. All these collisions generated heat, along with heat generated by the decay of radioactive elements, which melted much of the rocky material. The force of gravity would have pulled the liquid or semi-soft material into a spherical shape. As the planet cooled, it would have retained that spherical or nearly spherical shape.

Smaller objects, like many of the small satellites of the planets, as well as most asteroids (or, more correctly, "minor planets"), are not spherical. This may be because the object never got hot enough to become molten because of its small size, or it may have been part of a larger object that was broken up by a collision with another object.

Answer 3

Some People say it gravity but space does not have gravity.
Take a clear glass of water, pour some cooking oil in it (from a couple of inches above the glass so the oil goings down to the bottom of the glass, What happens to the oil as it is rising back to the top?.......If forms sphere's. Why? because the force is equal on all sides.

Now the plants according to science , When they were first (formed) were liquid masses. If gravity was the cause then they would have to be spinning.( the rotation of a planet is what causes gravity). What happens to a liquid mass when you spin it.? it flies out all over the place. So the planets had to be partial solid mass before they started spinning.

Answer 4

Planets are spherical because gravity pulls them into that shape, which is the most economical energy state once they reach a certain critical mass.

Answer 5

Yeah, gravity pulls equally inward to the center of the planet creating a round shape.

Answer 6

Nature is very lazy and would like to conserve the space. Among a given set of three dimensional shapes, SPHERE occupies the least amount of space in 3D.

Atleast this is what I read from "Brief History of Time" by Stephen Hawking.

Answer 7

it is because we are spinning. if you spin something it the air, you will notice that it starts to form a spherical shape. the same is true with the planets

Answer 8

Are they spherical or is the action of spinning giving the illusion of a perfect sphere?

Answer 9

Not all of the planets and moons are exactly round. Even the earth is slightly pear shaped.

Answer 10

lacking gravity,other than their own, particles stick together in the most uniform shape possible, and that is a sphere.

think of it this way, with a sphere gravity from the center is equel in all directions, all other shapes would require non uniform distribution of gravity.

Answer 11

Because gravity pulls equally in all directions.