2006-12-17 01:22:06 · 9 answers · asked by rajeevan 1 in Science & Mathematics ➔ Astronomy & Space
all objects are attracted to each other in proportion to their mass (ask newton). so if you have two atoms, they will try to get close and orbit around some point. if you have three, they will all try to get close to each other around some point. if you have a billion atoms, they will all try to get close to each other around some point, and so on.
the easiest way for all the atoms to be close to each other without being out of balance (gravitationally speaking) is to form a sphere, where the furthest distance is equidistant all the way around, and hence the force vectors are also equidistant.
think of the moon being a cube. the gravitational pull on the corners of the cube from the center point would be greater than on faces, which are less distant from the center point. the corners would mash in toward the center, so gravity would even out.
now think of mountains versus oceans. the earth in not perfectly round, but it wants to be (also see newton for this).
2006-12-17 01:30:57 · answer #1 · answered by otis_hobson 3 · 0⤊ 0⤋
Sphere has the least volume of any geometrical 3-D shapes.
Shape of any celestial body is determined by gravitational forces.
In case of a planet/star gravity is directed inwards i.e. towards the centre.
This tendency will compel the shape of the object/body in such a way that it would occupy the least volume.
Since sphere has the least volume planets/starts(most objects in space) are in sphere shape.
There are some exceptions though:
1. binary stars too close to each other are not spheres.
their matter tends to arrange themselves around thei mutual Centre of Mass.
2. astronomical bodies near Black holes are mutilated by enormous gravitational pulls.
2006-12-17 09:23:22 · answer #2 · answered by Som™ 6 · 2⤊ 0⤋
In a low to zero g environment like space, when masses begin to form a body via gravity, the body will attract more mass equally in all directions (gravity pulls in equally in every direction) this results in spherical or near spherical bodies. Howver, For very large bodies like the earth, even if they start out somewhat non-spherical, gravity tends to pull them toward spherical shapes, again gravity pulls equally in all directions resulting in a sphere. By the way, the earth is not quite spherical, it is more like a slightly squashed sphere, but it's a very small affect.
2006-12-17 10:58:40 · answer #3 · answered by ZeedoT 3 · 1⤊ 0⤋
The majority of objects in space are not in sphere shape...
Objects only become spherical if they have enough mass to force them int a sphere...
There are many more dust particles and other objects that do not have enough mass to become a sphere...
2006-12-17 09:49:52 · answer #4 · answered by Charles B 2 · 0⤊ 1⤋
gravity and spheres have the lowest volume i guess lol
2006-12-17 09:30:59 · answer #5 · answered by ablock 781 2 · 0⤊ 1⤋
Spheres are cool! I guess that's why?
2006-12-17 11:51:27 · answer #6 · answered by AD 4 · 0⤊ 1⤋
Becuse of its gravity that makes its shape
2006-12-17 10:37:40 · answer #7 · answered by Killzone 2 · 0⤊ 1⤋
Because of gravity.
2006-12-17 09:25:15 · answer #8 · answered by No I Dont Like You 3 · 0⤊ 1⤋
because all of them are revolving and rotating.
2006-12-17 09:24:37 · answer #9 · answered by pranjal d 1 · 0⤊ 1⤋