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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 |
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Solar Sytem
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 |
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Solar Sytem
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. |
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Solar Sytem
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. |
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Solar Sytem
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 |
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Solar Sytem
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. |
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Solar Sytem
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 |
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Solar Sytem
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. |
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