Solar System Question

[Jaheria]

Hello,

Can people here answer a question that I have been wondering about for a while?

Is the solar sysem shaped like in the common diagram, where the planet orbits are more or less aligned in a 2 dimensional alignment around the sun. Are they close to that shape or are the completely at different angles and simply shown that way in the diagram?

If they are a differnet shape could someone please post a picture of what they more accurately look like?

Thanks

[Kaptain Klevtsov]

More or less as per the diagram. Theory has it that the planets form from a flat plane of dust which is in the same rotational arrangement as the sun, which also forms from the same stuff. After the sun collect senough stuff to ignite, it blows away a lot of the rest of the accumulated star dust, leaving a bit from which the planets are formed.

Well thats what I read anyway.

Kaptain Klevtsov

[beamish]

that's pretty much as I understand it too.

[EA2007]

Yeah thats pretty much it.

Another way to explain it is to look at Saturn and its rings. We can use this as a model for the solar system whereby Saturn is the Sun and the rings are the flat plane where the planets arise.

[algol]

yeah most of the planets follow that model. don't some of the dwarf planets orbit outside this plane?

[Ant]

There is some inclination between orbits though, for example Jupiter can have a decliantion of around +25degrees and at the moment it's -25 degrees (or there abouts).

This doesn't mean (I don't think that) that Jupiters orbit has a peak/trough of 50 degrees - you have to take into account the inclination of Earth's orbit as well.

I might be wrong.

[Jaheria]

Thanks that answers my question. It seems quite signifigant to me that it would be that way. Like realising that the earth isnt flat, but in reverse. Maybe Im just thinking too much hehe

[algol]

try picturing the solar system as an atom. something my old chemistry teacher used to say

[Astro_Baby]

As far as I know the planets are more or less 'flat' in the plane of the solar syatem with the exception of Pluto whose orbit is quite inclined to the plane of the other planets by about 30'

[GazOC]

ex-planet Pluto.

[algol]

still a planet!!!! just a dwarf one.

i'm calm again. anyone else think they misssed a trick naming these dwarf planets? i think makemake and eris sound nowhere near as good as doc, sleepy, grumpy etc.

[GazOC]

Ah yes, sorry!!

[algol]

just get a little defensive mate, they shouldn't mess with the order of things.

[Ant]

I have just checked and Jupiters inclination is only 1.3 degrees - so I was way off and the solar system does indeed look like a fried egg.

Ant

[GazOC]

just get a little defensive mate, they shouldn't mess with the order of things.

That was always my thinking, leave Pluto alone but classify the other objects as dwarf planets (or whatever) as they are discovered. Then I read an interview with a professional astronomer that totally changed my way of thinking, he said that 'grandfathering' in Pluto as a planet was no way to do science, things should be classified as far as possible on their properties and characteristics, not just because they were discovered first.

I'm not saying the IAU have got the system exactly perfect but I think they either had to re-classify Pluto our be prepared to allow MakeMake, Eris etc. and all the similar objects yet to be discovered in as planets, otherwise they'd be letting sentiment govern science.

[algol]

what if the majority of exoplanets are jupiter size though? wouldthat mean that mercury or mars would be de-classified as they dont fit the trend? or even us?

[John]

what if the majority of exoplanets are jupiter size though? wouldthat mean that mercury or mars would be de-classified as they dont fit the trend? or even us?

I guess, as our knowledge expands, we have to face up to re-classifying things from time to time - I think thats the point that Gaz's post makes. If objects on the scale of Jupiter or larger are more common than smaller worlds then the Earth may well need to be re-classified as a minor planet or similar.

John

[barkis]

Poor old Pluto, it sickens me that the re designated it, and perhaps it highly inclined orbit was the straw that did it, combined with it's diminutive size, which only became of relevance when the found those other lumps of coal. Size should not be considered. Anyway, how much further out from Pluto is it to the first bigger bit? Who coined the phrase Trans Neptunian anyway? Kuiper Belt Strays is a better term,

and I am sure Pluto is too near the Solar System to be classed as one of those.

Someone get the measuring tape out.

Ron.

[GazOC]

Yes John, IMHO you need to be willing to look at new evidence and be prepared to make changes based on that evidence, not stick with something "because thats how its always been".

We've already done the "big one" 200 years ago when they moved our species in with the apes, that must have been a far bigger shock to people than the current planet naming problem.

[GazOC]

I think the distance thing is a gray area, I'm not sure how you could scientifically classify Pluto as one type of object and Quaroar, Eris, MakeMake etc as another type of object based on a few AU here or there?

[EA2007]

what if the majority of exoplanets are jupiter size though? wouldthat mean that mercury or mars would be de-classified as they dont fit the trend? or even us?

The majority found so far are jupiter size and larger, yet we do not have the technology to detect earth-sized planets. I think the smallest to date is still some 5x more massive than Earth.

No doubt over the coming years we will be seeing more smaller planets being found.

[algol]

who knows, perhaps the earth isdestined to become a "Minor" Planet. what a sad day that would be

[John]

who knows, perhaps the earth isdestined to become a "Minor" Planet. what a sad day that would be

I don't know, since Carl Sagan's book "Pale Blue Dot" I've always thought that Earth was rather insignificant cosmologically speaking - it just happens to be our home.

John

[Astro_Baby]

I did think that Jupiters inclination was smaller than you said but I didn't have any reference books to hand earlier.

Plutos inclination is given at 17' The next highest is Mercury at 7'

The old book I got for my birthday still has Pluto listed as a planet though its first edition in 1981 actually argued that it shouldnt be and that we should really reconsider classifying objects, The author got his wish I suppose.

Maybe my science teacher at school, a rather crusty old lady called Miss Smith was right after all, she always looked a bit dubious whenever Pluto was mentioned. I put it down to her age and assumed it hadn't been discovered when she was at school. Maybe she just had doubts about its viability as a planet after all.

[davekermito]

Back to the original question (no offence!), if you compare the position of the planets in the sky in relation to the ecliptic, you can see how far they 'stray' off the plane of the solar system.

The majority will be almost on it, give or take 1 deg. This will give you a decent idea:

Photo by Alan at Walsall AS