DU astronomy experts: I read recently that all planets in our solar...

[brush]

Last edited Thu Jan 20, 2022, 05:36 AM - Edit history (1)

system rotate the sun on the same plane. Anyone have an idea if this is the usual order of things, that we know of, in the universe? I mean is there some law of physics that doesn't allow planets to rotate a star on different planes?

Our large planets like Saturn and Jupiter with many moons are sort of miniature solar systems and IIRC their moons don't rotate on the same plane.

[Wounded Bear]

1. Not an expert, but I think that is the "norm" as far as is known...

since planetary systems tend to start out as a disk surrounding the parent star, planets tend to form on a plane.

Moons can be somewhat different. Some moons may have been "captured" objects that took up orbit around planets after they formed. There could be other reasons moons don't orbit on the equatorial plane of the planet, like collisions, or near collisions that knock them off a 'normal' orbit.

The truth is, though, that it isn't necessarily known. They're still working on it.

[brush]

3. Good thoughts, especially on moons. Thanks.

[Marcuse]

2. Yes, the Plane of the Ecliptic.

[Wounded Bear]

4. I believe Pluto is off the plane of the eccliptic by 15-20 degrees or so IIRC...nt

[cstanleytech]

11. Well its also no longer considered a planet either rather its a dwarf planet and its orbit

could be due to its original one being disturbed millions if not billions of years ago thus knocking it off kilter.

[Igel]

12. I think its orbit is prograde.

It's a Kuiper Belt Object.

[brush]

5. Excellent. The video answers my questions.

[Roy Rolling]

6. Pluto is a little off

So it got demoted…

https://images.app.goo.gl/uis26fhoEozUbSyk8

[keithbvadu2]

7. 1+

[eppur_se_muova]

8. Do all planets orbit in a flat plane around their suns? (earthsky.org)

This was the first hit from Google:

https://earthsky.org/space/planets-single-plane/

It's worth considering that captured planets -- which are probably rare, although captured moons are not -- may very well have inclined orbits. It's been suggested that Pluto may have been captured this way. I don't know if anyone has studied whether orbital resonance effects would tend to bring such orbits closer into the ecliptic plane.

[brush]

10. Thanks for the link. Very interesting reading, and the commentors...

also introduce ideas and questions.

[Marcuse]

9. Which way is up?

Funny. We perceive Sol system as revolving counter clockwise only because of our northern bias.

[Igel]

13. Ultimately, the claim is different.

Do the star and its planets (resulting from a protoplanetary disk) pretty much obligatorily revolve in the same direction?

Yes.

Why? Because science.

Conservation of angular momentum.

The only problem will be that it's possible for planets to flip if they're not stabilized, or be influenced by encounters in a way that seriously messes with their axis of rotation.

[Buckeye_Democrat]

14. I'd expect MOST planets to rotate on the same plane...

... because of how stars (suns) develop in a swirl of molecules and bigger particles in the first place.... with some of those particles not gravitationally pulled into the star but rather into each other as they continue their orbit around the central mass.

Conservation of angular momentum, in a nutshell.