Which force causes Rotation and Revolution?

[Bluespace]

i am just curios about the topic,

what force is behind the these rotation and revolution , Gravity? centrifugal force?
why planets goes alway in the same orbital path? why its not fading or changing

how this all began ? as one object need some external force to make it move at first, so how theses rotation and revolution begin?

sorry i am just a curious computer science student, if this was foolishness forgive me

[BrainDead]

Now that's an interesting question...

I know that we have planets which feature retrograde rotation, but do we
have any evidence for retrograde orbits anywhere in the universe?

If we found a planet with a retrograde orbit, wouldn't it have to be a
captured wanderer of some kind?

Presumably, all planets orbit their primary stars in the same orbital
direction because they all formed from the same source of material when
the solar system was formed. Since the newly formed primary was spinning
in one direction, the planet-forming material would all be thrown off into
the same orbit. Yes?

Curious again.

[Malenfant]

Now that's an interesting question...

I know that we have planets which feature retrograde rotation, but do we
have any evidence for retrograde orbits anywhere in the universe?

If we found a planet with a retrograde orbit, wouldn't it have to be a
captured wanderer of some kind?

Presumably, all planets orbit their primary stars in the same orbital
direction because they all formed from the same source of material when
the solar system was formed. Since the newly formed primary was spinning
in one direction, the planet-forming material would all be thrown off into
the same orbit. Yes?

Curious again.

Pretty much. The disk that the star and planets form in is spinning. While you'd think that everything should spin and rotate in the same direction, you have gravitational and tidal interactions and collisions between objects that can tip them over and can tip them so far that they're tilted at angles greater than 90 degrees (like Uranus and Venus). They're not really rotating "the wrong way" - if you were to tip them the "rightway up" then they'd be rotating in the same direction as the other planets. They just look like they're rotating retrograde because of their tilt.

Moons can have retrograde orbits because they're captured objects (eg Triton, Phoebe). Again, because of gravitational interactions or collisions, they may be orbiting the sun in the opposite direction to how the planets usually orbit.

We don't have any planets in our own system in retrograde orbits (though we do have moons that are) - but yeah, if we did find a planet with a retrograde orbit elsewhere then it'd almost certainly have to be a captured body.

[hank]

We don't have any planets in our own system in retrograde orbits (though we do have moons that are) - but yeah, if we did find a planet with a retrograde orbit elsewhere then it'd almost certainly have to be a captured body.

There are comets in retrograde orbits. They may or may not be captured bodies. For planets with substantial mass, I would guess that both retrograde orbits and extrasolar captures are very unlikely.

- Hank

[BrainDead]

Moons can have retrograde orbits because they're captured objects (eg Triton, Phoebe).

Thanks for that explanation Malenfant... I did not know that Phoebe
and Triton featured retrograde orbits, so this was useful from a very basic
standpoint.

Funny, I've viewed those moons and their planets many times, but I never
even noticed the orbits. Sheesh! At any rate, the "captured wanderers"
theory seems apparent when you also view the orbital planes compared to
the other moons in those two systems.

Again, thanks for the explanation. Always facinating here.

[buggs_moran]

There are plenty of captured clockwise (prograde?) orbiting objects in our system. (just speed up time around Jupiter and watch the moons) But I think you might be right in stating that they would have to be captured Bob. The initial motion of the protoplanetary disk would govern the final orbits of the planets. Conservation of angular momentum demands that a contracting, rotating object (such as an interstellar cloud) must spin faster as it's size decreases (as a protoplanetary disk would). That law fixes the orbit directions of larger bodies (planets). However, smaller bodies (moons, asteroids, comets, maybe KBO's) would be heavily influenced on orbital motion by larger ones & collsions. Anyway, orbital motion is only counter-clockwise because we view the solar system from the "top" in reference to the Earth. From the "bottom" orbits are clockwise. I wonder however if there is a force analogous to the coriolis effect on Earth in a spinning galaxy that would "influence" the spin of intersellar clouds that ultimately become solar systems...

[Bluespace]

but what about the forces behind Rotation and revolution?
gravity? magnetic feild? centrifugal???

is gravitational force produced from the high speed spinning? or is it because of any particular elements(matters) ?

[selden]

Gravity is associated with mass. Mass is measured by how much force is required to accelerate an object. The more massive an object is, the more force is required to accelerate it to a particular velocity. The more massive an object is, the more gravitational force it generates.

[hank]

but what about the forces behind Rotation and revolution?
gravity? magnetic feild? centrifugal???

is gravitational force produced from the high speed spinning? or is it because of any particular elements(matters) ?

If I recall correctly:

Orbital motion is primarily due to the force of gravity between the sun and planet, applied to the planet's tangential velocity (its current speed and direction of motion). If the gravitational force were to cease, the planet would fly away from the sun in a straight line. If the planet's tangential velocity were stopped, the planet would fall into the sun on a straight line. The combination of the tangential velocity and the sun's gravitational force causes the planet to move in an elliptical orbit. (There are many other influences on the planet's motion, but their effect is negligible.) The gravitational force is due to mass, a basic property of all matter. The force is directly proportional to the combined mass of the sun and planet, and inversely proportional to the square of the distance between them (decreases with increasing distance). This is all according to Isaac Newton.

Rotation is sustained by the conservation of angular momentum. Keep in mind that a force is not require to sustain motion, just to change it's rate or direction.

- Hank