Where does the solar system end?

bhsup

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I cannot seem to get a definitive answer to this. I've read oort cloud in some places, the heliosphere in others, just beyond the Kuiper belt objects in another place.

Really, it cannot be that hard to give a boundary can it?
 
It ends when you get to the sign that says "Thank you for visiting the Solar System - Please come again!"
 
I hate to say this, but where's Perf when you need him?

I'd venture to guess that it's where the sun's gravity stops pulling you in.
 
It ends at the heliopause at a boundary called the "termination shock", where the sun's solar wind is slowed to subsonic speed by interstellar wind. It's around 76 - 100 AU from the sun. It's where the sun's influence ends and interstellar space begins.

Also the existance of the Oort Cloud is not confirmed. It's supposed to be a region where long-orbital period comets originated, at about 50000 - 100000 AU from the sun (1 light year). The comets in the Cloud are only loosely bound to the solar system and only ventures into the Solar System proper only when disturbed by gravity of passing stars or gas giant planets.

I preferred the heliopause as the limit of the solar system and I consider the Oort Cloud as just a band of insignificant icy rocks deep-frozen in interstellar space.
 
Turner said:
I hate to say this, but where's Perf when you need him?
Freakin' playing Civ 4!

Turner said:
I'd venture to guess that it's where the sun's gravity stops pulling you in.
Well there's a problem with that idea, it changes! Stars in the galaxy go around in crazy go nuts fashion, it's not the orderly circular orbits you see with planets in the solar system, no stars go to and fro and every which way. To give in example in a few million years a star known as Gliese 710 will be just over a light year away from us.

Some argue that some solar wind based phenomena determines the demarkation point, but I find that rather absurd given that bodies like Sedna go way beyond that. I'd say the best bet is to go with whenever the Oort cloud ends, of course the problem with that is we know just about squat about the Oort cloud, and really have no clue where it ends (or begins). So I say the best thing to do is sit back and wait to see what sorts of stuff we find lying out beyond the Kuiper Belt.
 
taillesskangaru said:
It ends at the heliopause at a boundary called the "termination shock", where the sun's solar wind is slowed to subsonic speed by interstellar wind. It's around 76 - 100 AU from the sun. It's where the sun's influence ends and interstellar space begins.
Well to be correct it's where solar wind ends or at least slows down (I don't fully understand the whole thing), it's not where the Sun's influence ends. The Sun's gravity well is far beyond these points.

taillesskangaru said:
Also the existance of the Oort Cloud is not confirmed.
I think the indirect evidence for icy bodies (the long-period bodies) beyond the small area confined by the KBOs is enough to support the existance of the Oort Cloud

taillesskangaru said:
It's supposed to be a region where long-orbital period comets originated, at about 50000 - 100000 AU from the sun (1 light year).
Well, with the discovery of Sedna many are discussing the possibility that it may be significantly smaller

taillesskangaru said:
The comets in the Cloud are only loosely bound to the solar system and only ventures into the Solar System proper only when disturbed by gravity of passing stars or gas giant planets.
I think loose binding counts for something. They certainly have an impact on the innermost parts of the solar system and they are bound to the solar system, just because they are easily disrupted by other solar systems is IMO not a good enough excuse to throw them up.

taillesskangaru said:
I preferred the heliopause as the limit of the solar system and I consider the Oort Cloud as just a band of insignificant icy rocks deep-frozen in interstellar space.
Of course those iceballs are significant. Comets have a role in the behavior of the solar system and any discussion of the solar system that excludes them seems to be rather silly.
 
I agree that the heliosheat definition is silly; there's just too many bodies orbiting the Sun in paths crosssing it.

Given the average stellar density in the Sun's neighbourhood, it seems unlikely that stuff with orbits going out to a lightyear or more can long remain attached to the Sun on astronomical timescales. The question is how much closer objects are gonna be snatched away.
 
Perfection said:
I think loose binding counts for something. They certainly have an impact on the innermost parts of the solar system and they are bound to the solar system, just because they are easily disrupted by other solar systems is IMO not a good enough excuse to throw them up.

Agreed. My personal feeling on where the solar system ends is where objects are no longer under the influence of the sun's gravity... which could be as far as lightyears away.... However, '2 lightyears' or something arbitrary like that doesn't work either; the solar system has no perminate boundry but rather an ever-changing one.

And there are no other solar systems, only other star systems :p
 
VRWCAgent said:
I cannot seem to get a definitive answer to this. I've read oort cloud in some places, the heliosphere in others, just beyond the Kuiper belt objects in another place.

Really, it cannot be that hard to give a boundary can it?

It's where all the Dwarf planets live :mischief:

Leatherneck said:
It ends when you get to the sign that says "Thank you for visiting the Solar System - Please come again!"

http://en.wikipedia.org/wiki/Solar_System#Farthest_regions

Thank you for Visiting the Solar System - Please Come Again!
Alpha Centauri - 4.365 light years
Little Chef - 2.148 light years
Motel 6 - 0.883 light years
 
I've always gone with the heliosphere, as by definition that's what the term is for.

To suggest that the limit has to be where there is no influence by the Sun on anything, is a bit extreme.

...And if anyone here suggests a Dwarf Heliosphere I'll...!
 
Heres a weird question, I'll try to put it into words properly: Our sun is in a spiral arm of the galaxy along with of course many others. Heres the tricky part. Whats the internal structure of a 'spiral arm'. Would an arm almost be like a hollow tube, with most of the stars revolving around the edges?

edit: or I guess I should say, revolving around an empty center.
 
Ok, thanks Last. I was picturing the stars in the spiral arms revolving as the arms themselves revolve.
 
Where does the solar system end?

At the edges of the petrie dish.
Oh, you haven't heard ? The entire universe is nothing more than a science experiment taking place in a cosmic sized petrie dish.

HTH
 
Ugh. I'd hate to see how much changing there's gonna be for various Civ scenarios. :D
 
Bozo Erectus said:
Heres a weird question, I'll try to put it into words properly: Our sun is in a spiral arm of the galaxy along with of course many others. Heres the tricky part. Whats the internal structure of a 'spiral arm'. Would an arm almost be like a hollow tube, with most of the stars revolving around the edges?

edit: or I guess I should say, revolving around an empty center.
This is a good time to ask wiki (because it can explain it better than I can)
http://en.wikipedia.org/wiki/Spiral_galaxy
 
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