Solar Sytem

Hi,

Just wondering.......

There have been several references to 'the edge of the solar system' in the
media over the last few weeks, where exactly is the edge of the solar
system? My understanding would be that it would be the furthest part
affected by the sun; gravity, light etc.

It goes without saying I am a bit of a novice with this stuff, but I do find
it enthralling.

Thanks

There have been several references to 'the edge of the solar system' in the media over the last few weeks, where exactly is the
edge of the solar system? My understanding would be that it would be the furthest part affected by the sun; gravity, light etc.

"Termination shock" (We have 2 satellites about there now!)

"Oort cloud" (further out)

Google both (with the quotes).

I am sure there are several other boundaries that could be cites that I
don't know about.

Gravity extends outwards basically unto infinite distance, getting weaker.
The only wrinkle in that really is that gravity probably propagates at c,
so some parts of the universe probably aren't "feeling" gravity from our
solar system yet.


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie

Fleetie wrote:
There have been several references to 'the edge of the solar system' in the media over the last few weeks, where exactly is the
edge of the solar system? My understanding would be that it would be the furthest part affected by the sun; gravity, light etc.

"Termination shock" (We have 2 satellites about there now!)

Not really. Some say it's at the heliopause and some other is at the
bow-shock front.

See also: http://en.wikipedia.org/wiki/Heliopause

Andrea T.

JRS: In article ,
dated Fri, 23 Jun 2006 19:41:58 remote, seen in news:uk.sci.astronomy,
PETER HUGHES posted :

There have been several references to 'the edge of the solar system' in the
media over the last few weeks, where exactly is the edge of the solar
system? My understanding would be that it would be the furthest part
affected by the sun; gravity, light etc.


Fundamentally, the solar system is a gravitationally bound system.

Therefore, ISTM that it extends as far out as it could maintain a small
body in bound orbit without the body wandering off into the rest of the
universe reasonably soon - akin to the Hill radius for a moon being
bound to its planet.

If some of the nearer stars are of similar mass, then the distance is
around a third of the way to the nearest of them, very roughly.

On that definition, solar systems do not touch, and are separated by
interstellar space.

Alternatively, one might take the limit as being the distance of the
remotest bound body, or the remotest known bound body.

If each element of space must be assigned to a specific solar system
(which seems silly except for administrative purposes) then one might
say that a point in space belonged to the body which exerted the
greatest gravitational field at that point.


If, however, one is interested in a specific type of physical
phenomenon, then the relevant edge must be where the nature of that
phenomenon becomes more characteristic of out-system rather than in-
system. Hence the heliopause, and also Niven's singularity.


From the media point of view, the edge depends on the lesser of their
own understanding and their estimate of that of the target audience - in
other words, it is fairly arbitrary.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

In message . com,
writes

Fleetie wrote:
There have been several references to 'the edge of the solar
system' in the media over the last few weeks, where exactly is the
edge of the solar system? My understanding would be that it would
be the furthest part affected by the sun; gravity, light etc.

"Termination shock" (We have 2 satellites about there now!)

Not really. Some say it's at the heliopause and some other is at the
bow-shock front.

See also: http://en.wikipedia.org/wiki/Heliopause

Andrea T.

Even if you don't believe in the Oort cloud, isn't the edge of the solar
system defined by the orbits of objects such as long period comets and
Sedna (about 800 AU? Well outside the heliopause.

On Sat, 24 Jun 2006 20:51:28 GMT, in uk.sci.astronomy , Jonathan
Silverlight wrote:

In message . com,
writes

Fleetie wrote:
There have been several references to 'the edge of the solar
system' in the media over the last few weeks, where exactly is the
edge of the solar system? My understanding would be that it would
be the furthest part affected by the sun; gravity, light etc.

"Termination shock" (We have 2 satellites about there now!)

Not really. Some say it's at the heliopause and some other is at the
bow-shock front.


Even if you don't believe in the Oort cloud, isn't the edge of the solar
system defined by the orbits of objects such as long period comets and
Sedna (about 800 AU? Well outside the heliopause.

My understanding is that the termination shock is generally regarded
start of the edge, and the helioipause as the end of the edge. The
oort cloud is considered to be outside the solar system.
--
Mark McIntyre

Jonathan Silverlight wrote:
In message . com,
writes

Fleetie wrote:
There have been several references to 'the edge of the solar
system' in the media over the last few weeks, where exactly is the
edge of the solar system? My understanding would be that it would
be the furthest part affected by the sun; gravity, light etc.

"Termination shock" (We have 2 satellites about there now!)

Not really. Some say it's at the heliopause and some other is at the
bow-shock front.

See also: http://en.wikipedia.org/wiki/Heliopause

Andrea T.

Even if you don't believe in the Oort cloud, isn't the edge of the solar
system defined by the orbits of objects such as long period comets and
Sedna (about 800 AU? Well outside the heliopause.

The influence of solar gravity well extends, virtually, to infinity so
I won't take that as a measure of what constitues or definies the edge
of the solar system. I'd rather take the solar wind as a parameter.

Andrea T.

wrote:
Jonathan Silverlight wrote:
In message . com,
writes

Fleetie wrote:
There have been several references to 'the edge of the solar
system' in the media over the last few weeks, where exactly is the
edge of the solar system? My understanding would be that it would
be the furthest part affected by the sun; gravity, light etc.

"Termination shock" (We have 2 satellites about there now!)

Not really. Some say it's at the heliopause and some other is at the
bow-shock front.

See also: http://en.wikipedia.org/wiki/Heliopause

Andrea T.

Even if you don't believe in the Oort cloud, isn't the edge of the solar
system defined by the orbits of objects such as long period comets and
Sedna (about 800 AU? Well outside the heliopause.

The influence of solar gravity well extends, virtually, to infinity so
I won't take that as a measure of what constitues or definies the edge
of the solar system. I'd rather take the solar wind as a parameter.

Andrea T.

How about making it the most remote aphelion of objects orbiting the
sun? The Oort cloud (hypothetical) or Sedna (known)?

How about this line of reasoning: Pluto has historically been
considered a planet. Planets are intrinsically part of solar system.
2003UB313 is quite similar to Pluto and has aphelion at ~97AU.
Therefore, solar sytem extends to at least 97AU.

Greg

Dr John Stockton wrote:
JRS: In article ,
dated Fri, 23 Jun 2006 19:41:58 remote, seen in news:uk.sci.astronomy,
PETER HUGHES posted :

There have been several references to 'the edge of the solar system' inthe
media over the last few weeks, where exactly is the edge of the solar
system? My understanding would be that it would be the furthest part
affected by the sun; gravity, light etc.


Fundamentally, the solar system is a gravitationally bound system.



Fundamentally funny,funny,funny.I am sure Newton thanks you from the
grave but how was the poor guy to know that the solar system is not
exempt from influences which causes it to move, in unison with the
other visible stars, in one direction around the galactic axis.

"Cor. 2. And since these stars are liable to no sensible parallax from
the annual motion of the earth, they can have no force, because of
their immense distance, to produce any sensible effect in our system.
Not to mention that the fixed stars, every where promiscuously
dispersed in the heavens, by their contrary actions destroy their
mutual actions, by Prop. LXX, Book I." Newton


You speak with that wonderful pseudo-authority that looks more pathetic
as the years go by.When we should be considering the influences of the
solar system's galactic orbital motion on planetary heliocentric motion
you and your colleagues are still stuck with local solutions of a
gravitationally bound solar system.




-

Therefore, ISTM that it extends as far out as it could maintain a small
body in bound orbit without the body wandering off into the rest of the
universe reasonably soon - akin to the Hill radius for a moon being
bound to its planet.

If some of the nearer stars are of similar mass, then the distance is
around a third of the way to the nearest of them, very roughly.


On that definition, solar systems do not touch, and are separated by
interstellar space.


Alternatively, one might take the limit as being the distance of the
remotest bound body, or the remotest known bound body.


If each element of space must be assigned to a specific solar system
(which seems silly except for administrative purposes) then one might
say that a point in space belonged to the body which exerted the
greatest gravitational field at that point.


If, however, one is interested in a specific type of physical
phenomenon, then the relevant edge must be where the nature of that
phenomenon becomes more characteristic of out-system rather than in-
system. Hence the heliopause, and also Niven's singularity.


From the media point of view, the edge depends on the lesser of their
own understanding and their estimate of that of the target audience - in
other words, it is fairly arbitrary.


--
© John Stockton, Surrey, UK. Turnpike v4.00MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't MailNews.



Amazing that nobody has a good old laugh at Newton's conceptions and
his determination to fit terrestial ballistics into planetary
motion,the later localised gravity well ideas are funny and made
funnier by the fact of the solar system's galactic orbital motion,my
word,what a well that would be !!!!!.I particularly like your posts
John,they are sincere in their own way even if hopelessly empirical in
nature.

Still,it would be nice to see an intelligent and astronomically
intuitive person appear in order to make things productive again but
this is for selfish purposes.




Therefore, ISTM that it extends as far out as it could maintain a small
body in bound orbit without the body wandering off into the rest of the
universe reasonably soon - akin to the Hill radius for a moon being
bound to its planet.

If some of the nearer stars are of similar mass, then the distance is
around a third of the way to the nearest of them, very roughly.

On that definition, solar systems do not touch, and are separated by
interstellar space.

Alternatively, one might take the limit as being the distance of the
remotest bound body, or the remotest known bound body.

If each element of space must be assigned to a specific solar system
(which seems silly except for administrative purposes) then one might
say that a point in space belonged to the body which exerted the
greatest gravitational field at that point.


If, however, one is interested in a specific type of physical
phenomenon, then the relevant edge must be where the nature of that
phenomenon becomes more characteristic of out-system rather than in-
system. Hence the heliopause, and also Niven's singularity.


From the media point of view, the edge depends on the lesser of their
own understanding and their estimate of that of the target audience - in
other words, it is fairly arbitrary.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't MailNews.