Number of possible planets in a solar system.

[Foullows]

I was wondering if there has been any discussion or studies investigating the possibilities of having dozens of planets in a single solar system.&nbsp; I know our solar system had 9 with the old way of categorizing planets (I'm not sure what the official count is now).&nbsp; The reason I ask this is because of watching the movie serenity in which they say that they had found a solar system with 'dozens of planets and hundreds of moons' and I thought to myself, is that even possible? <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I was wondering if there has been any discussion or studies investigating the possibilities of having dozens of planets in a single solar system.&nbsp; I know our solar system had 9 with the old way of categorizing planets (I'm not sure what the official count is now).&nbsp; The reason I ask this is because of watching the movie serenity in which they say that they had found a solar system with 'dozens of planets and hundreds of moons' and I thought to myself, is that even possible? <br />Posted by Foullows</DIV></p><p>&nbsp;</p><p>Interesting question, welcome to Space.com!!<br /><br />Well, there's no reason to assume there's a hard limit, like there can only be 12 or 14 or 50.</p><p>Our knowledge of how stellar systems form is still in the early stages. Up until 10 years ago we only had one example to work with, our own. Since then we've been discovering many stellar systems, but really are just starting to get a feel for the variety out there.</p><p>Here we have 8 planets, 3 dwarf planets (so far) and millions of asteroids and comets.</p><p>Basically, it is limited only by the size (mass)&nbsp;of the gas cloud that forms the solar system, how much of that mass remains once the star ignites (because the radiation and wind from the star clear out the smaller particles) how close the nearest high energy star is, how many pieces the dust and debris gets divided in to.</p><p>My educated guess is that there's no reason therecan't be dozens of planets around a star, and probably quite a few have none.</p><p>It's really a roll of the dice as to how a particular system develops.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[Foullows]

I suppose that makes sense. Thanks for answering my question. I'm sure I'll have more bizarre questions in the future to ask. <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I suppose that makes sense. Thanks for answering my question. I'm sure I'll have more bizarre questions in the future to ask. <br />Posted by Foullows</DIV><br /><br />That's what we're here for!<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[doubletruncation]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I was wondering if there has been any discussion or studies investigating the possibilities of having dozens of planets in a single solar system.&nbsp; I know our solar system had 9 with the old way of categorizing planets (I'm not sure what the official count is now).&nbsp; The reason I ask this is because of watching the movie serenity in which they say that they had found a solar system with 'dozens of planets and hundreds of moons' and I thought to myself, is that even possible? <br /> Posted by Foullows</DIV></p><p>There are some limits based on the stability of the system. If you were to drop another planet just anywhere into our solar system, for instance, there is a good chance that it would not be stable over 4.5 billion years (one or more planets would end up being ejected after mutual gravitational interactions).&nbsp; See for example:http://online.kitp.ucsb.edu/online/kitp25/tremaine/ especially the summary at:&nbsp; http://online.kitp.ucsb.edu/online/kitp25/tremaine/oh/23.html - this process is what sculpted the Kirkwood gaps in the asteroid belts for example ( http://www.daviddarling.info/encyclopedia/K/Kirkwood_gaps.html ).</p><p>You could add more planets in very distant orbits, but the density of raw material for making planets drops with distance for a young star forming planets (what MeteorWayne mentioned).&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[Smersh]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I was wondering if there has been any discussion or studies investigating the possibilities of having dozens of planets in a single solar system.&nbsp; I know our solar system had 9 with the old way of categorizing planets (I'm not sure what the official count is now).&nbsp; The reason I ask this is because of watching the movie serenity in which they say that they had found a solar system with 'dozens of planets and hundreds of moons' and I thought to myself, is that even possible? <br /> Posted by Foullows</DIV></p><p>Welcome to SDC!&nbsp;<br /> </p><p>Here's a couple of extracts from a BBC article from February, concerning the possibility of extrasolar Earth-like planets, but which also mentions the possibility of many more planets, remaining to be discovered in our own Solar System:</p><p><strong><font size="2" color="#008000">Some astronomers believe there may be hundreds of small rocky bodies in the outer edges of our own Solar System, and perhaps even a handful of frozen Earth-sized worlds.</font><font color="#008000"> </font></strong></p><p>However:</p><p><strong><font size="2" color="#008000"> Speaking at the AAAS meeting, Nasa's Alan Stern said he thought only the tip of the iceberg had been found in terms of planets within our own Solar System. </font></strong></p><p> <strong><font size="2" color="#008000">More than a thousand objects had already been discovered in the Kuiper belt alone, he said, many rivalling the planet Pluto in size. </font></strong></p><p> <strong><font size="2" color="#008000">"Our old view, that the Solar System had nine planets will be supplanted by a view that there are <font color="#800000">hundreds if not thousands</font> of planets in our Solar System," he told BBC News. </font></strong></p><p> <strong><font size="2" color="#008000">He said many of these planets would be icy, some would be rocky, and there might even be objects with the same mass as Earth. </font></strong></p><p> <strong><font size="2" color="#008000">"It could be that there are objects of Earth-mass in the Oort cloud (a band of debris surrounding our planetary system) but they would be frozen at these distances," Dr Stern added. </font></strong></p><p> <strong><font size="2"><font color="#008000">"They would look like a frozen Earth."</font></font></strong></p><p><strong>Full article here.&nbsp;</strong></p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <h1 style="margin:0pt;font-size:12px">----------------------------------------------------- </h1><p><font color="#800000"><em>Lady Nancy Astor: "Winston, if you were my husband, I'd poison your tea."<br />Churchill: "Nancy, if you were my wife, I'd drink it."</em></font></p><p><font color="#0000ff"><strong>Website / forums </strong></font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>There are some limits based on the stability of the system. If you were to drop another planet just anywhere into our solar system, for instance, there is a good chance that it would not be stable over 4.5 billion years (one or more planets would end up being ejected after mutual gravitational interactions).&nbsp; See for example:http://online.kitp.ucsb.edu/online/kitp25/tremaine/ especially the summary at:&nbsp; http://online.kitp.ucsb.edu/online/kitp25/tremaine/oh/23.html - this process is what sculpted the Kirkwood gaps in the asteroid belts for example ( http://www.daviddarling.info/encyclopedia/K/Kirkwood_gaps.html ).You could add more planets in very distant orbits, but the density of raw material for making planets drops with distance for a young star forming planets (what MeteorWayne mentioned).&nbsp; <br />Posted by doubletruncation</DIV></p><p>Absolutely correct.&nbsp; In fact the stability question, over an arbitarily long period of time, is one for which we do not have the ability to provide an answer.&nbsp; It is tied up in the multi-body dynamics problem.&nbsp;Sso far as I know the stability of our own solar system has not been determined.&nbsp; What is known through simulation is that the planetary orbits&nbsp; won't go wild for quite a long time.</p><p>The more interacting bodies that you throw into the mix and the stronger their interaction with one another, the more likely the system is to eventually exhibit instability.&nbsp; So there is probably a practical upper limit on the number of sizeable bodies that could co-exist in a system.&nbsp; I don't know what it is, but I would guess that the number is fairly modest.</p><p>This is actually a very interesting and very difficult mathematical problem.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>