why are planets sphere like?

Question

why arent they more of a triangle or squared? are there any other then sphere-like planets?

Answer 1

The shapes of planets are spheres because the sphere is the shape you get when the race is a tie. Each piece of the planet tries to get to the center. A really really long time ago the heaviest pieces of our planet which are made of metal, not rock, won this race and they are now at the center of Earth, metal wins over rock. But each piece of rock that makes up the rest of the planet is still trying to win the race and because most of them are pretty much the same it comes out a tie, and the shape of a tie is a sphere. So planet's are spheres because the sphere is the shape you get when no one piece of the planet is much different from any other and all the pieces are trying to reach the center. Why do the pieces of a planet try to reach the center, I'm sure you know, it's the force of gravity.

Some little moons, like the moons of Mars, and most asteroids don't have enough gravity to start the race to the center. In those cases the shapes can be very bumpy, even like a potato.

Answer 2

The gravity of a large object is sufficiently strong to pull it into a spherical shape. If the object is small enough it can continue to exist in an odd nonsymmetrical shape. For example, while our Moon is a sphere, both moons of Mars, Phobos and Deimos, are irregular, potato-shaped objects.

http://filer.case.edu/sjr16/mars_moons.htm

Such objects are very common in and around the Solar System. They would outnumber spherical astronomical objects by billions to one, including as they do all the asteroids and comets, many minor moons, the objects in the Asteroid Belt, the objects in the Oort Cloud, and the billions of objects in Saturn’s rings and so on. Just that most of these are small and nobody worries about them much.

A sphere has the property of having an infinite number of planes of symmetry. That is, it looks the same from any angle. A planet shaped like a pyramid! Now that would be a sight. But we can all see how a sphere would form naturally with physical forces working from all sides. How would a pyramid planet form? If we saw one, we would almost instantly think that it was the product of some highly advanced technology.

Btw, planets are not PERFECT spheres anyway. Take the Earth for example. Please. Boom tish.... Like nearly all planets, the Earth spins on its axis. This caused the early Earth, when molten, to bulge a little more around the equator. Once it cooled down, the bulge became permanent. If you measure the great circle of the equator, you will find it to be a liitle longer than the great circle that passes thru the Poles. In a sphere, of course, those 2 measurements would be the same. So technically the Earth is a spheroid, although it comes so close to a sphere, it is hardly worth mentioning. But I did anyway.

Answer 3

All planets are spheres more or less. Their own gravity makes them round...it pulls equally from every possible side...that is why planets are round.

One of the key definitions of a planet is that it must have enough mass to have great enough gravity to give it a rough, spherical shape. This is one of the things that got Pluto into trouble. Yes, it has enough mass to alter its shape into a sphere, but so do a few asteroids...they would have had to include at least one...Ceres...as a planet based solely on that.

CK has a very good explanation for it, one that I intend to use next time I am trying to teach this.

Answer 4

The spherical shape of the earth is due to various factors., like gravity, centrifugal force, magnetism, etc.

But gravity plays a central role, remember that the formation of cosmological entities take place over millions of years, only those that have the most stable shape survive the various forces that act on it like the gravity of other beings. What shape is the most stable? -- Sphere!

the shape of the body is determined by the extent of internal gravity and other attractive forces exerted on the body. since there are no external factors, the force of gravity is equal on all sides, hence the spherical shape.. The bigger the planet or star you can expect it to be a more perfect sphere.. (although it is also affected by the gravity of other bodies)

There are non sphere like objects too. but the formation of those are not solely on their own. they are often chips of other celestrial bodies that attain a non-spherical shape due to collision/abrasion etc. however the more absurd the shape the more unstable is its movement.. for eg asteroids. Once they start stabilizing they are also chistled into a sphere.

Answer 5

Virtually ALL planets, moons & suns are Spheres. There's some kind of Scientific Law (which I can't remember) that explains why all spinning objects quickly assume the shape of a sphere. It saves energy or something- I'm not sure... It IS an interesting observation though...

Answer 6

No they are no longer appropriate spheres, and actual that's been measured and that they are no longer appropriate spheres. besides to reply to your question. a million. they're on the factor of appropriate spheres via fact they have a great adequate mass to grow to be sphere-like. in fact, for the period of the whole "is Pluto a planet" debates, planets have become defined as our bodies of mass that are sufficiently massive to grow to be spheroid (i'm paraphrasing, you could wiki the perfect definition). 2. they are no longer appropriate spheres via fact the Earth rotates, and you get centripetal forces. The Earth is actual wider around the equator. Som minutiae, that's actual considerable - there's a reason Cape Canaveral is placed in Florida - to take income of the weaker gravity there the two via great altitude, and extra importantly the value gained from the spinning Earth. Likewise, the Olympics held in Mexico city broke varied international information and this has been attributed to the weaker gravity there.

Answer 7

I believe it has to do with how gravity pulls things. For example, if two meteors get close enough to each other, and one is large enough to establish some kind of gravitational field, the smaller one will start to orbit the larger. Eventually they will collide and form one entity. When the object increases in size with the addition of new meteors or debris, so too does its gravitational field, and so other things might be pulled into it. As the object continues to grow larger there is a gravitational center that is established, and everything that adds onto it gets pulled as close as possible to the center. Naturally, as we are talking about a three dimensional envrionment, the resulting constriction of material takes on a spherical shape.

Answer 8

a sphere is the natural result of an object that was once mostly liquid being held together by its own gravity - a sphere is the most mass with the least surface area possible - and the sphere is slightly flattened by the Earth's spin.

Answer 9

A Triangular earth ? Now that would be interesting !! IT'S called PHYSICS AND THE LAWS THEREOF !! And until we develop better tecno tools the 2nd part of your question is REDUNDANT at best !! There are 8 more spherical planets in OUR solar system.Get yourself a beginners book on astrology and do some READING !!Who knows you might even RETAIN some of what you read. Wouldn't that be a hoot ??

Answer 10

All planets are formed box-shaped originally , but over the years space debris rounds off the corners , and they end up looking like a basketball .