Why they aren't cobe,cone or ...?
Give me good reason.
2007-03-18 00:57:44 · 5 answers · asked by mehrdad 1 in Science & Mathematics ➔ Earth Sciences & Geology
Planets are not spherical. The solid portion of planets is obloid (egg shaped). The atmosphere is almost perfectly spheroid do to gravity. The effect of gravity is the square of the distance so as a planet forms from plasma and or space debris each portion looks for the lowest point around the center of gravity. Magnetic interaction causes a less than perfect shape or planets would be spheres.
2007-03-18 01:05:41 · answer #1 · answered by Mike M 4 · 0⤊ 0⤋
Because, most of them have been solidified / in the process of solidification from an initial gaseous/vapour phase. Since, It is the spherical / ellipsoidal shape has minimum surface tension and nearest to a stable state, most of them attain spehericity. Almost for identical reasons, you will find mercury droplets or any liquid droplet on a non-cohesive surface take the shape of a sphere.
But when the planets / asteroids are formed by breaking up of a solid mass, they do not have a definite shape.
2007-03-18 03:32:00 · answer #2 · answered by saudipta c 5 · 0⤊ 0⤋
Maybe at one time, there were all different shapes. Given the fact there is no air in space, space is a vaccum, friction is not a factor, therefore generating heat from rotation or orbiting is not possible. Maybe all the millenia of space dust, debris, metoers, comets, solar flares, the other space debris that shoots through space has worn down all the planets while they have been in a rotational motion, therefore wearing down the corners and eventually presenting these celestial bodies with a new shape. I am probably pretty far-fetched here, but is a theory only.
2007-03-18 01:08:46 · answer #3 · answered by djbest1973 2 · 0⤊ 0⤋
For a given volume a sphere has the minimum surface area hence minimum energy. Hence all natural bodies try to acquire spherical shapes to have minimum energy condition. This holds good for planets too.
2007-03-18 06:42:43 · answer #4 · answered by mandira_nk 4 · 0⤊ 0⤋
Smaller bodies could be any shape.
As the mass grows the strength of the material that comprises them is over come by the increasing gravity and takes on a spherical shape.
If Mount Everest could be put on the moon it could be much higher.
If it were put on a neutron star it may be so small you couldn't see it.
It's strictly gravity and strength.
2007-03-18 01:06:44 · answer #5 · answered by Billy Butthead 7 · 2⤊ 0⤋