2007-09-28 05:09:05 · 20 answers · asked by MOON WITCH 3 in Science & Mathematics ➔ Astronomy & Space
Its the most equal shape when all the internal forces are acting around a single point.
Everything in the Universe is trying to equalise itself.
2007-09-28 22:35:18 · answer #1 · answered by futuretopgun101 5 · 2⤊ 1⤋
Gravity is the reason why planets are round. After a critical size and mass, gravity becomes strong enough to overcome the strength of the materials that make up a celestial body and deform them into a spheroidal or a spherical shape. This shape is a state of equilibrium, where the mass of an planet sized object is distributed equally or nearly equally throughout the volume of space the object occupies. An object with an irregular shape would have a very variable gravitational field at it's surface whereas a spherical object would not. A sphere is not only the most stable shape an object can have, but one where the most mass will fit into the least volume.
2007-09-28 13:22:47 · answer #2 · answered by Anonymous · 2⤊ 1⤋
Gravity tends to draw things as close to the centre of gravity as possible, to do this each point must lie on the surface of a sphere and so over time and with enough mobility the rock is molded to an approximate sphere (smaller bodies cooled to quickly to gain a sperical shape like the asteroids). The earth and other rocky planets bulge obout the equator due to centrifugal force generated by the rotaion of the planet.
2007-09-28 12:27:20 · answer #3 · answered by zebbedee 4 · 3⤊ 1⤋
1. A serious answer: Because of the natural law of least resistance. The spherical shape has the least volume for the same amount of mass - however sometimes distorted to oval shape by rotation.
2. Just joking: God found that it is the sexiest shape, (we understand him well don't we?), so anytime he looks out his window he feels good.
2007-09-28 12:54:25 · answer #4 · answered by Wintermute 4 · 2⤊ 0⤋
Gravitational attraction is a spherical symetrical force,ie ,the force is equal in all the directions.so when a planet forms,in its forming phase all the particals are attracted equally towards the centre,so all heavenly bodies are mostly round.But there are always exceptions in nature.You can take HYPERION, one of Saturns many moons.Its not at all spherical as its a very porous body.So the mass ia very less as its very porous.Since mass is propotional to gravitational attraction ,lower mass means lower attraction.So ,there is not enough force to form a sphere and hyperion remains an irregular body.
2007-09-28 12:31:43 · answer #5 · answered by t-rex 2 · 4⤊ 1⤋
because of the gravity ,which is a law of physics,like travelling objects like asteroid's will be of many shapes, planets are stable i.e. in a motion with other planets they survive because of each other therefore a sphere is the perfect shape under a gravitationally force...love-on-ya!,bowie.
2007-09-28 12:34:43 · answer #6 · answered by Anonymous · 1⤊ 1⤋
because the gravity that acts as they are forming is equally strong in all directions so a sphere is produced (actually most planets bulge a little around the middle due to centrafugle forces of their rotation)
2007-09-28 12:13:43 · answer #7 · answered by hoegaarden_drinker 5 · 11⤊ 1⤋
Because if they were square they would rotate around the sun in a box formation.
2007-09-28 12:12:21 · answer #8 · answered by ? 5 · 3⤊ 1⤋
Gravity shapes them into a sphere.
2007-09-28 14:31:04 · answer #9 · answered by Feeling Mutual 7 · 1⤊ 1⤋
during formation they were in liquid form due to very high temperature.due to surface tension property they became spherical .
2007-09-28 12:17:13 · answer #10 · answered by Anonymous · 3⤊ 0⤋