this is about planets!?

Question

is earth exactly spherical?if so how could a thing so big like earth could form a definite and precise shape?

Answer 1

Its not a definite shape.It probably just looks like a sphere from far.
With all the buildings how could it be in a definite shape.I hope thats what you were asking.

Answer 2

It has to do with two principles at work, gravity and hydrostatic equilibrium.

Gravity is pretty much what pulls everything towards the center.

Hydrostatic equilibrium means that, on billion-year time scales, even things as rigid as rock behave somewhat like fluids. Since gravity deriving from a given mass is equal at any distance, regardless of the direction from that mass, the entire mass of the earth is pulled into the shape that minimizes potential energy (energy derived from position in relation to gravity) and equalizes the pressures inward and outward. That is, all the matter tries to get the closest it can to the origin of the gravity, and stops when something gets in the way and pushes back. That shape naturally approximates a sphere.

Now, on truly cosmological timescales, and neglecting any rotation or outside forces, any mass would come pretty much arbitrarily close to a perfect sphere. However, given the external forces of the moon's and sun's gravity and the rotational motion of the earth, the ideal sphere is pulled into a "spheroid", or like a sphere but somewhat flattened.

Take a look at tides, if you want to see gravity at work on a huge scale. The motion of tides is essentially, the moon's and sun's gravity pulling the most flexible portion of the earth (the oceans) away from an ideal sphere.

Answer 3

Earth isn't exactly spherical. Because it is spinning, it bulges out at the equator and the poles slightly squish together. I'm not sure though how it formed its somewhat spherical shape.

Answer 4

Earth is not a perfect sphere. It bulges near the equator due to that portion of the earth being closer to the sun, therefore it experiences a slightly stronger force of gravity.

Planets do tend to be near spheres because of their own gravity, which is large due to the large mass. On the other hand asteroids are not spherical because the have little gravity due to smaller mass.

Answer 5

im sure the earth is not exactly round. We have mountains and canyons which make this almost impossible. from a distance, it appears to just be a big round green blue gray ball, but i dont' believe its perfectly spherical.

Answer 6

no its not exactly, but its really close

i believe its spinning causes the equator to bulge out a little bit
however, i think i heard somewhere that if u shrunk the earth down to the size of like a handball it would be closer to being completely smooth - even with all the mountains and stuff - then those rubber handballs u can buy i the store

Answer 7

Hi Kid!
No. The Earth is what is called an "oblate spheroid."
Wikipedia.org defines it as "a rotationally symmetric ellipsoid having a polar axis shorter than the diameter of the equatorial circle whose plane bisects it."
See: http://en.wikipedia.org/wiki/Oblate
Remember that you can put questions into search engines phrased such as "shape of the Earth." That's all there is to it!
Best regards,
Dave.

Answer 8

Because of Gravity and force exerted since it is spinning at such a high speed.

Answer 9

I've often heard the Earth is pear shaped... Coincidentally, so was my ex-girlfriend.

Answer 10

The earth is thicker at the equator.