why are the planets rotating about their axes?

Answer 1

The planets in our Solar System (now only eight - Pluto got sacked today) rotates about their axis because of "conservation of angular momentum".

Angular momentum is given by L=mwr^2 where m is the mass, w is the angular velocity in radians per second, and r is the radius of the circular motion. Due to conservation of angular momentum, if the radius of the orbit decreases, then its angular velocity must increase (as the mass is constant).

All planetary and stellar systems are born from the collapse of dense interstellar clouds. The clouds may originally be very large (even thousands of light years across). Consider a portion of the cloud the collapses from a size of a light year or so to the size of the solar system. That is a huge change in the size of the system. So, the very slight rotation that the cloud has in the beginning is increased dramatically when the collapse takes place.

Anyways, even our Sun spins on its axis because of the original angular momentum that was there in the solar nebula from which it formed. And all orbital motion of the planets (circling around the Sun and spinning about their axis) are due to this orginal angular momentum.

Answer 2

Because of the way planets form; solar systems start off as clouds of dust. As they collide with one another, they clump (or "accrete"), and because the constituent particles are moving in different directions when they collide, they can impart an angular momentum to the whole. Over time, as more and more of these larger clumps get attracted towards one another through gravity, the larger accretion will have a certain spin to it from all the added bits. The reason why most planets rotate around an axis that is more or less perpendicular to the plane of the solar system is that the dust cloud you started with tends to also rotate as a whole while the sun is forming in the center, and so the accretion disk around each planet will tend to be in the same plane as all the other planets, and thus all the added particles impart momentum within that plane, causing each planet to rotate around an axis perpendicular to that plane.

Answer 3

Anything tha rotates would necessarily have an axis of rotation along the line of its spin. All bodied in motion in spce hav a tnedncy to move with a spin only . even in teh earth's atmospher when you throw a stone into the air , it moves along its trajectory with a sin only . It is not so in the atmospher only. This charracter isseen while bodies move in space also. may be it is a natural tendency of teh moeveing boies to keep their trajectory in a path of equilibrium. The planets are not perfect lobes and their center of gravity and axis of rotation miight lie not exactly at its center and the body moving in any direcion naturally assume a positin tha might keep its mass evenly distributed around the point that could form teh center along the line of its axis . This must casue a spin.
Another reason could be tat when the mass that has formed into a planet was first thrown apart by the Big Bang should hae been thrown with some force that sould give it a rotaion and as you know any body that is in motion in space should continue to be so for ever unless and untill it is interfered with So teh body that got a twist or turn at the time of its tearing away from the primordial matter should continue to maintain that turn aklso along its axis . Furthe as the big masses of objects in space have a force of mutual attraction . The masses that separet themselves by force due to te big bang while parting from the other mass should have been subjected to a stronger pull and this combined with the force of teh intial thrust or throw from teh parent body must have had a stronger pull on the side of the mass closer to it at it tore away form teh parwntr mass and this should have set a spin in motion and this spin should continue for ever as the body rotates around the bigger body that exerts a pull on the samller ones . And there are no other forces or friction to reduce or change the speed of spin or rotation of te planets also . they continue for ever .

Answer 4

Its due to two effects. The planets themselves are not round, it is slightly eggshaped. The orbit is not circular but oblong. Those effects made the planets tilt. It is just so perfectly balanced that the planet doesnt keep tilting.

Spin an egg on the larger end and it will tend to tilt and not stay upright. The friction on the bottom causes the egg to tilt and eventually collapse. In space, magnetic friction does the same.

Answer 5

Did you hear that Pluto is not longer conciderd a planet?

Answer 6

They need to rotate to make toilet water whirlpool when we flush. Where would we be without that?

Answer 7

Conservation of angular momentum.

Answer 8

Because the plants are too get off thier chiars.

Answer 9

axe em

Answer 10

To piss off the religious wackos.