Why is the solar system flat?

Question

The planets revolve around the sun on a 2D plane.

Answer 1

Look up "disk accretion", a popular theory about the formation of our solar system. This theory explains that as the cloud of dust and gas that formed our system was condensing, it's rotational motion caused an effect similar to centrifugal force which flattened the spinning cloud into a spinning disk.

I should note that the system isn't exactly flat, a couple of the outer planets have taken on orbits that are quite askew to the disk that the inner planets are aligned with.

The following web site has some simplified explanations of solar system formation:
http://www.windows.ucar.edu/tour/link=/our_solar_system/formation.html

and more in-depth info at:
http://www.dtm.ciw.edu/akir/Seminar/seminar.html

Answer 2

The solar system is not quite flat, but it is very close. This is due to the process which created the planets which make up the solar system. They were created from the remnants of an accretion disk of matter as the sun formed. Why a disk, though? Remember that all matter has mass, which means it has its own gravitational field, no matter how small. A rotating disk is simply the most stable formation for a collection of particulate matter, with all particles attracting one another, around a central primary gravitational point (which eventually formed the sun).

The solar system is not a perfect plane because there will always be slight perturbances in the system. This is especially true after the sun forms, and more so after the remaining matter in the disk starts to "clump up" on its own to form individual planets. With so many large gravitational sources about, the system becomes very complex, and smaller objects caught within one or more of these fields can be pulled around in rather chaotic patterns. Hence, we have objects such as comets in highly eccentric eliptical orbits, and a 9th planet Pluto with an orbital plane a full 17 degrees off the ecliptic.

Answer 3

While not perfectly flat it is pretty close. The reason for this is because it is rotating. Imagine a lump of very soft clay on a spinning table. As you spin the table that clay will flaten out on the table. The same is true of the planets, asteroids and other objects in our solar system (at least the objects that have been here since the beginning of our solar system that is). Because of their velocity they would like to shoot straight out into space but the force of the suns' gravity keeps that from happening.

It is believed that Pluto was "captured" by our solar system after its creation (much like a comet is, in fact some believe that Pluto is nothing more than a very large comet on a huge orbit) which would explain why it's orbit is on a different axis.

Also, proffalken1975, atoms are not arranged like a solar system at all. This is a common misconception as the simplest way to describe an atom in a diagram does make them look very similar to a solar system.

Answer 4

It is not (quite).

The planets revolve around the Sun along the eccliptic which is the path which the Sun, Moon and planets follow accross the sky.

However the plane of each planet is at a diiferent angle (a bit like a stack of dirty plates where each one is stacked at a slightly diffrent angle).

Pluto orbits at a completely different angle to the other planets and some recently found KBO's (Kuiper Belt Objects) orbit the Sun at highly irregular angles!

The reason the main bulk of the solar system appears flat is because it is spinning and like anything that spins it will create its own stability.

Answer 5

there is now debate concerning Pluto's status as a planet. so, probably shouldn't use that to attack the question. It actually behaves quite a bit like a comet.

Im sure if one were to calculate the relative planarity of our solar system (relative to randomly axised orbits) one would find it to be amazingly planar (even with Pluto).

Assume the "things thrown from the sun" theory of planetary formation. Consider the sun a set of merry-go-rounds aligned on the sun's axis, of diameters such that they form a sphere. They are rotating at the same degree-rate. The tangential velocity will be greatest for the largest diameter MGR, that at the equator. So if something were going to be spun off, it would occur here. Material expelled distant from the equator would still be expelled perpendicular to the axis, and at a lower velocity. This material would be acted upon by the gravitational field of the more equatorial sun, pulling back into the fold.

This is one possible simplified explanation.

Answer 6

In the same way that if you tie an apple to a piece of string and then whirl it around it will take on the shape of a flat plane. The suns gravity holds on to the planets in just the same way since they are all directly held by its gravitational pull...all except Pluto which has an orbit slightly different and at an oblique angle...Several thoughts have emerged as a result of this, one being that it is far enough from the sun to be influenced by another force which causes this deviation...maybe another small star for instance

Answer 7

Well, it's not completely flat. Atoms are not flat. I think that the gravitational field or the magnetic field of the sun (due to the spinning motion) more heavily favor a flatter solar system, or, perhaps, our solar system is flat (or close to flat) because there was a greater chance for life to form on earth when the other planets were aligned so. For example, life could not have formed If there was not a large planet such as Jupiter to take the impact of asteroids for us. So maybe we live here because it is flat (or close to flat). I do know that galaxies are flat (or cl- you know the rest) because of cintripical force from the high speed (or relatively high speed) that is held together by supper massive black holes.

Answer 8

The sun revolves on the same axis that the planets do around it. Far as I know, most believe the planets came out of the sun in its very early life stages. In this case, they would orbit on the same plane.

Answer 9

It's almost flat. That comes from how the solar system formed. After a new star fires up there is left over debrie spinning around it. The velocity flattens the debrie out to a disk. It is from this debrie that planets from, so that's why later on they still remain more or less on the same orbital plane.

Answer 10

If you want to know the answer, look at this representation of the magnetice field of a celestial body:

http://helios.gsfc.nasa.gov/parker.gif

The gravatational field looks much the same. It is stronger in the horizontal plane because of the way the sun spins. All the planets also travel around the sun in the same direction.

Did you know the equator of the sun rotates at one rotation every 25 days, but near the poles it rotates once every 35 days?