By that, I mean, why do planets always orbit… horizontally(?) around the sun. Why not vertically? Space is a 3D space, I’d course. So why would the planets not end up going up as well as sideways?
Edit: Space science is a lot more complicated than I thought, and I am here for this rabbit hole. Ty everyone for your answers so far!
In: 2352
[removed]
1) It’s because it’s the net momentum of the entirety of the solar system. Initially it was all chaos with orbits all around 3D space in both directions. But as objects hit each other, they naturally tend to the overall net momentum of the whole system.
See for example [2:50 of this video](https://youtu.be/MTY1Kje0yLg?si=dbTwYx3xXhhLUJbx&t=168). Notice how at first, they are all orbiting at different directions, but eventually, they all tend to the same direction. The same effect happens even in 3D space.
2) It is not perfectly horizontal. There are some deviations. [Especially as you get further out into the solar system.](https://qph.cf2.quoracdn.net/main-qimg-a5f76425b453b2fb0edcec8e579d6a92-lq)
Imagine you and nine friends going down a wide waterslide. At the beginning you are bumping into each other a lot. But as time goes on, you find yourselves going more or less parallel and collisions are more rare. By colliding you have evened out your sliding direction.
Most big stuff in our solar system orbit in planes in the same directions because the average motion of all the things colliding around that gravitational centre was going that direction to begin with. There is only one equilibrium but many ways to be uneven.
Every planetary body has mass.
Mass creates gravity
Over billions of years each piece of mass pulls and effects the others
The solar system now is effectively the net average of every other body pulling eachother to themselves
It can be overshadowed in general education but gravity has really distant effects, while the sun is obviously the strongest, earths gravatic effect can affect objects over 3 billion light years away
Of course that effect is infinitely miniscule and overpowered by everything else local to affected bodies, but still.
Tldr the solar system is largely flat because everything pulls everything to itself
It is called [https://en.wikipedia.org/wiki/Orbital_inclination](https://en.wikipedia.org/wiki/Orbital_inclination) and is quite close to the same for planets and most other object close to the sun. It is quite close to the equatorial plane of the sun too.
If you look at objects farther away too like the Kuiper belt and Oort cloud the inclination rate increases and at the Ooortcloud you find all possible orbits https://planetplanetdotnet.files.wordpress.com/2023/05/image.png
The explanation is the planets and the sun was not formed intentionally. All is formed by collapsing gas clouds. When everything starts to orbit the common center of mass there will be more collision between objects that have different orbital inclinations.
let’s just look at circular robbits then orbital speed only depends on the distance from the center. Objects that orbit in the same plane will not collide with each other but will intersect all other orbital planes at the same distance. So the only way for stuff to orbit with no collision is in a disc
Over time the results of collision and gravitational effect will result in that most materials have close to the same inciation where they can orbit with the least amount of collisions.
Orbits are not just circles, they are all ellipses so the effect is that most stuff will orbit in close to the same plane.
Even after planets are formed they interact with gravity. The direction of the force with tidal effect on the object makes them all move towards the same plane.
The reason there is more variation farther away from the sun is there is a lot less stuff there The interaction that made the center pare closet a plane has a smaller not realy effect at all so objects in the Oort cloud orbit the sun in all plants.
The total mass of the Oort cloud is around 2 times the mass of the Earth. The cloud. The distance from the sun ranges from 2,000 to 200,000 AU. 1 AU is the distance between Earth and the sun. All planets aw with 30 AU from the sun. The Oort cloud is made up of billions of objects that orbit in 3D.
[removed]
You have also to realize that the circles/ellipses described is usually a relative-to-the-sun description for basic knowledge – so that you can introduce it to people learning about it without getting too technical at first. The reality is that even the sun moves through space (seldom shown in these depictions) which means the circles/ellipses are shown as if it all moved in a straight line towards your viewpoint, while if seen from any other point beside it all, it looks more like open corkscrews following the sun.
Even this gif is a simplification and not entirely correct, but you get the gist of it: [https://tenor.com/view/earth-and-sun-earth-orbeting-sun-flat-earth-planets-orbits-gif-15150791](https://tenor.com/view/earth-and-sun-earth-orbeting-sun-flat-earth-planets-orbits-gif-15150791)
A spinning object has more speed at the equator than at the poles and therefore can throw bits and pieces farther. Sun is such spinning object and planets have formed from “splashes” from it. This video demonstrates the physics pretty well: https://www.youtube.com/watch?v=FVo2qdXxQ7o
Horizontally and vertically are only relative terms in space. What you mean is that the planets generally orbit around roughly the same plane. Solar systems begin life as clouds of dust of various elements. These clump together in barycenters and form stars or planets and these clouds are called protoplanetary disks.
The reason why they turn into disks from uniform clouds and why they spin is because as all the mass surges towards specific points and clumps this inevitably induces a spin, to the clumps being formed and the gas cloud as a whole, like pizza dough flattening out as it’s spinned. A “dominant” plane emerges so to speak which is an orbital plane that has the majority of the mass of the material in the cloud. As planets form they “clear up” the rest of the molecules in the cloud either because their gravitational attraction pulls them to them or through collisions. Over billions of years this clears up most random bodies not in the dominant plane and the result is a solar system where most planets are orbiting roughly in the same plane. Foreign bodies like asteroids or comets that come from outside the solar system may still orbit at other planes but the majority of the material orbiting in other planes has been essentially “vaccuumed up” by the larger bodies.
Because they all coalesced over time out of the same spinning disc of matter. It mostly collapsed to the middle and formed the sun, but clumps out in the disc collapsed into the planets. But it’s all the same disc of matter still spinning.
Latest Answers