Why are all the planets perfectly round, like someone made them in a factory in China?

Question

Have you seen a bang?? If you have, what is left over is shrapnels of different shapes and size.. So how come the big bang, created a perfect set of globes dancing around the sun in such a repetitive, regulated, pattern

Answer 1

Well, not perfectly spherical. Saturn, for instance, spins pretty fast on its axis which cause it to be noticeably off round (equatorial bulge).

The answer as to why bodies tend to be spherical is gravity. Anything that deviates from spherical under a high level of gravity will act as if it was a high mountain, which will crumble under its own weight. When reaching a certain scale, all material behave as it there were liquid, gravity does that.
Seeking minimum elevation, bodies will therefore settle under a spherical shape, subject to perturbations from spinning (as I mentioned above) and tidal effect from other large nearby bodies.

Answer 2

I am sure the shrapnel's were made somewhere on earth if not in China. So they have that shape. But the case of planets or space objects is a different story. The result of Big-bang is still not fully explainable. To explain scientifically you need to learn a lot of science theories. I will try put in layman's way. Do you know the reason why soap bubble is spherical? Did you see them (if the film is thick) getting distorted by external contact? If not exactly similar it is something like this. After the Big-bang all the matter was in vapor state. During condensation the vapor gets closer and closer due to gravitational force. The gravitational force is equal in all direction (in the absence of any distorting factors). Hence the condensed product would get spherical shape.

Answer 3

The 'Big Bang' is believed to have happened about 13 or 14 billion years ago. Our Solar System is only about 4.5 billion years old and was formed from a very large cloud of gas and dust which slowly condensed into a large central mass with severla smaller masses orbiting around it. As the central mass developed sufficient pressure and temperature at it's center, a fusion reaction began and Sol (our Sun) was born. As time progressed, the smaller orbiting masses cooled and solidified to become the planets in our Solar System.

You need to learn a bit about the evolution of a star and its planets. Maybe take a course in General Astronomy where the evolution of the Solar System is discussed. Then you won't have to ask these kinds of questions.

Oh, one other thing. The Earth is *not* perfectly round. It's actually kinda 'pear' shaped. And none of the other planets are perfectly round either.

HTH ☺

Doug

Answer 4

The Big Bang created the matter out of which the Universe is made, but the stars, planets, and bigger moons were created by the force of gravity acting on the scattered matter. Gravity always acts toward the center of mass, and is stronger the closer you get to that center, so as the clumps of matter became bigger, any irregularities were filled in to produce the spheroid shapes we see. By the way, the "globes" are not perfect spheres, but are slightly fatter around their equators due to outward centrifugal forces. This is most evident in the "gas giant" planets Jupiter, Saturn, Uranus, and Neptune.

Answer 5

They're not quite round - they're elliptical, wider around the Equator than they are at the poles.

According to the Nebula Hypothesis (to me, the most likely answer), the reason the planets came to orbit the Sun in a (relatively) regular pattern is that the Sun formed from a cloud of gas and dust. The bits of gas and stuff began to stick together, due to gravity, and over a long period of time, the whole thing began to rotate around a centre of gravity as the Sun accreted more matter, with a disc spinning around it (a protoplanetary disk).

The matter in the disc also clumped together as the Sun had, forming larger bodies (planets) and leaving over some smaller debris (such as asteroids), all orbiting the Sun.

Because the matter was orbiting the Sun, as it formed the planets, they (mostly) continued to orbit the Sun in near-round, elliptical orbits (again, due to gravity). No planet orbits in a totally round path, though.

Hope that made sense, at times I confused myself. Put a maybe-better explanation of the disc thing in my sources.

Answer 6

The planets are round because the strength of the material they are made of cannot resist the force of gravity.
Small satellites like the rocks around mars are lumpy because they are strong enough to resist the gravity that tries to make them round
Mount Everest resists the gravity on earth,if you put it on a neutron star it may be only a fraction of an inch high.

Answer 7

they are not perfectly round, even the earth.
most odd size leftovers were sucked into another's gravity or thrown into outer realms of space

Answer 8

Gravity did it.

Answer 9

No idea , might be gravity
(:P)