Could someone please explain to me why every planet known to mankind is spherical in proportional mass?

Question

They all seem to be roundish

Answer 1

gravity.

If the matter that condenses into planets (or nearly any large body), it will try to pull in to a shape that allows most of the material to be as close as possible to the center of the body.

Something that isn't large enough for it's own gravity to affect it's shape won't form the sphere. Like asteroids.

Granted, if that mass is spinning fast enough, centrfiugal force may force it to bulge around the middle, perpendicular to it's axis of spin. Even the earth bulges slightly at it's equator.

Answer 2

Scientific answer : Gravity acting on mass, inducing spherical and eclliptical orbits and thus their shape as well.

Metaphysical answer : a circle has no beginning or end. Thus the planet symbolises the universe - there was neither a beginning nor is there an end. There had to be something before the Big Bang for it to happen in the first place.

Answer 3

Versus square planets? Most known planets are roundish because of their internal gravity pulling in mantle at the same pull all around. If there was an instibility in the planet's gravity and gravitational pull was less on a side than the rest, there would be rotational/revolval instability as well.

Answer 4

Gravity...The matter making up the planet is attracted towards the center of gravity in the middle of the planet. Gravity acts as a constant force and so depending on how much mass there is, the point from the ground to the center of the planet is roughly equal all around, just as a circle is a set of points equal from a center point.

Answer 5

Actually, any 7th grade science book can tell you this.

Its because whether its a Star, planet or moon, WHEN GRAVITY starts to spin it, all the matter congregates at the center, OUTWARD, meaning usually, an oblate spheroid. Or a SPHERE that's slightly flattened at the poles. So, the center of the planet will be "wider" then it will gently taper to the top of the planet which will slightly "flatten" out somewhat because of a lessening of gravitational pull.

ANOTHER INTERESTING QUESTION: Why do ALL MOONS in the Solar System (major moons anyways) ALWAYS show the same face to their planets?

Answer 6

Because gravity squishes everything to a central point thus making a circle, and friction will burn things natural into a circle. (why friction with the planets? Because they spin.)


Hey we should make an artificial square planet or moon. That'd be way sweet. You'd have 4hrs in a day Night, dusk, noon, and dawn. As the sun rotated and finally came at a direct angle at the face.

Answer 7

Many of the solid ones aren't exactly spherical (Earth itself is actually slightly wider around the equator), but, to the best of my knowledge, once an object is big enough to have its own gravitational pull, the pull exerts equal force on all sides of its mass, making a round body.

Answer 8

Actually, I don't know any that are rigid spheres. Most, like the Earth, are oblate spheriods. They have bulges around the equator caused by the centripital force as they rotate. Gravity just keeps the planet as one mass.

Answer 9

Planets are round because their gravitational field pulls every thing towards the center. The Larger the planet the flatter the surface.

Answer 10

The lack of gravity in space causes the material to form spheres. When the spheres start spinning, the force keeps the material in perfect spheres. Next time you get on a space shuttle, make blow some water out of a straw and watch what shape it forms in ;).