Possible Periodicity in Earth Impact from Oort Cloud Comets

[MeteorWayne]

<p>A very interesting article from Bill Napier and David Asher concerning Tunguska and earth impacts from Oort Cloud Comets. I may add some excerpts later.</p><p>http://star.arm.ac.uk/preprints/2009/539.pdf</p><p>Please ignore any overhyped headlines you may hear as this article has been misread and mishyped by New Scientist as "Dark Comets" then slaughtered by a medical reporter at "The Telegraph" in the UK. Shameful...</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>

 

[dragon04]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>A very interesting article from Bill Napier and David Asher concerning Tunguska and earth impacts from Oort Cloud Comets. I may add some excerpts later.http://star.arm.ac.uk/preprints/2009/539.pdfPlease ignore any overhyped headlines you may hear as this article has been misread and mishyped by New Scientist as "Dark Comets" then slaughtered by a medical reporter at "The Telegraph" in the UK. Shameful... <br /> Posted by MeteorWayne</DIV></p><p>I notice early on in the paper, they state that it could be either asteroidal or Oort based. The word periodicity was used, so what could possibly pertrub Oort cloud objects on a periodical basis? </p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[Archer17]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I notice early on in the paper, they state that it could be either asteroidal or Oort based. The word periodicity was used, so what could possibly pertrub Oort cloud objects on a periodical basis? &nbsp; <br />Posted by dragon04</DIV></p><p>Nibiru.</p><p><img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-tongue-out.gif" border="0" alt="Tongue out" title="Tongue out" /></p><p>:runs:<br /></p> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I notice early on in the paper, they state that it could be either asteroidal or Oort based. The word periodicity was used, so what could possibly pertrub Oort cloud objects on a periodical basis? &nbsp; <br />Posted by dragon04</DIV><br /><br />Gravitational effects from passing through the plane of the galaxy, where most of the galactic mass and molecular clouds are concentrated. The solar system 's orbit is not aligned with the galactic plane but rather passes above and below it during it's inclined orbit. <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>

 

[Archer17]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Gravitational effects from passing through the plane of the galaxy, where most of the galactic mass and molecular clouds are concentrated. The solar system 's orbit is not aligned with the galactic plane but rather passes above and below it during it's inclined orbit. <br />Posted by MeteorWayne</DIV></p><p>My Nibiru joke aside, this is a good answer IMO. I heard it referred to as "galactic tides."<br /></p> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>My Nibiru joke aside, this is a good answer IMO. I heard it referred to as "galactic tides." <br />Posted by archer17</DIV><br /><br />I believe they might have used that term in the paper (along with the molecular clouds more common near the plane..</p><p>{Wayne feverishly flipping pages...}</p><p>Yes, they did </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>

 

[derekmcd]

There's always the legitimate 'Nemesis' hypothesis.&nbsp; Unfortunately, as the years pass, it's less and less like that a companion to our Sun will be found. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>There's always the legitimate 'Nemesis' hypothesis.&nbsp; Unfortunately, as the years pass, it's less and less like that a companion to our Sun will be found. <br />Posted by derekmcd</DIV><br /><br />I believe as the years go on, the Nemesis hypothesis becomes more and more unlikely. If there were a large object in the outer solar system (even in the scattered disk) we would have found it by now. IMHO, the galactic tide source of disruption to the Oort cloud is far more likely, if it exists at all.</p><p>MW</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>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I believe as the years go on, the Nemesis hypothesis becomes more and more unlikely. If there were a large object in the outer solar system (even in the scattered disk) we would have found it by now. IMHO, the galactic tide source of disruption to the Oort cloud is far more likely, if it exists at all.MW <br /> Posted by MeteorWayne</DIV></p><p>IIRC, Nemesis is hypothesized to be a red dwarf companion star with a 26,000 year orbit that coincides with extinction events. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[halcyondays]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>IIRC, Nemesis is hypothesized to be a red dwarf companion star with a 26,000 year orbit that coincides with extinction events. <br />Posted by derekmcd</DIV></p><p>Thought the theory was 26 million years.</p>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thought the theory was 26 million years. <br /> Posted by halcyondays</DIV></p><p>stupid orders of magnitude errors <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-embarassed.gif" border="0" alt="Embarassed" title="Embarassed" />.</p><p>You are quite correct. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[derekmcd]

<p>Here's a lecture from Muller, one of collaberators of the Nemesis theory.&nbsp; Muller has an excellent series of lectures from Berkeley.&nbsp; He briefly discusses his theory starting about the 33 minute mark of the lecture.&nbsp; It's definitely not a crank theory.</p><p>http://www.youtube.com/watch?v=ERy-MTfgulc </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Here's a lecture from Muller, one of collaberators of the Nemesis theory.&nbsp; Muller has an excellent series of lectures from Berkeley.&nbsp; He briefly discusses his theory starting about the 33 minute mark of the lecture.&nbsp; It's definitely not a crank theory.http://www.youtube.com/watch?v=ERy-MTfgulc <br />Posted by derekmcd</DIV><br /><br />I'll try and go to the 33 minute mark. the fact is there is NO evidence whatsoever (as there should be) of any such an object. <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>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thought the theory was 26 million years. <br />Posted by halcyondays</DIV><br /><br />You do realize that an object with a 26 MY orbit would not be bound to the solar sytem, right? <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>

 

[halcyondays]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You do realize that an object with a 26 MY orbit would not be bound to the solar sytem, right? <br />Posted by MeteorWayne</DIV></p><p>I do, thanks.&nbsp; I was just&nbsp;correcting the hypothesis about Nemesis, that's all. Myself, I have never been very keen on the Nemesis concept anyway.</p>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I do, thanks.&nbsp; I was just&nbsp;correcting the hypothesis about Nemesis, that's all. Myself, I have never been very keen on the Nemesis concept anyway. <br />Posted by halcyondays</DIV><br /><br />I must correct myself. If did the math right, a circular orbit at 1.4 LY would be ~ 26 MY. Of course, that would not effect the Oort cloud like a more eccentric orbit would , which would make my statement correct, more or less. </p><p>I need to crunch some more numbers....</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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>A very interesting article from Bill Napier and David Asher concerning Tunguska and earth impacts from Oort Cloud Comets. I may add some excerpts later.http://star.arm.ac.uk/preprints/2009/539.pdfPlease ignore any overhyped headlines you may hear as this article has been misread and mishyped by New Scientist as "Dark Comets" then slaughtered by a medical reporter at "The Telegraph" in the UK. Shameful... <br /> Posted by MeteorWayne</DIV></p><p>That was a *very* interesting article by the way.&nbsp; I must say it does sound rather "plausible", especially watching the Shoemaker-Levy comet distintigrate into a bunch of diferent fragments before final impact.&nbsp; Thanks for the link. </p> <div class="Discussion_UserSignature"> It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. - Kristian Birkeland </div>

 

[Archer17]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Here's a lecture from Muller, one of collaberators of the Nemesis theory.&nbsp; Muller has an excellent series of lectures from Berkeley.&nbsp; He briefly discusses his theory starting about the 33 minute mark of the lecture.&nbsp; It's definitely not a crank theory.http://www.youtube.com/watch?v=ERy-MTfgulc <br /> Posted by derekmcd</DIV></p><p>I've read about Muller's ideas and agree that he's not your basic "crank" but I'm also skeptical regarding Nemesis. The primary problem IMO is, as MW already pointed out, lack of observational evidence for such a companion. Muller posits that this hypothetical red dwarf is close enough to be observed if we only knew exactly where to look (IIRC he mentioned it possibly being in or near the constellation Hydra) but I understand we did a comprehensive IRAS sky survey awhile back and didn't come across any Nemesis candidates.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[silylene old]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Here's a lecture from Muller, one of collaberators of the Nemesis theory.&nbsp; Muller has an excellent series of lectures from Berkeley.&nbsp; He briefly discusses his theory starting about the 33 minute mark of the lecture.&nbsp; It's definitely not a crank theory.http://www.youtube.com/watch?v=ERy-MTfgulc <br />Posted by derekmcd</DIV><br /><br />The existance of the distant binary TNO, QW322 pretty much precludes the existance of Nemesis.&nbsp; If Nemesis or Niburu or any such object&nbsp;existed, its gravtitational&nbsp;effects&nbsp;would have disrupted this extremely weakly bound distant TNO binary pair.&nbsp; You may recall that we discussed this already in this thread I started last year:</p><p>http://www.space.com/common/community/forums/?plckForumPage=ForumDiscussion&plckDiscussionId=Cat%3ac7921f8b-94ec-454a-9715-3770aac6e2caForum%3ad148ee4c-9f4c-47f9-aa95-7a42941583c6Discussion%3afc1388aa-b6e6-4002-83c4-f722a8ce15f6</p><p>The large separation implied a mutual-orbit period of at leastseveral years. Six years of tracking with the use of 4- to 8-mclass telescopes (<font color="#003399">Fig. 1</font>) resolved that 2001 QW₃₂₂, an objectin the main classical Kuiper Belt (<em><font color="#003399">6</font></em>), has a low-eccentricitymutual orbit with a separation of 105,000 to 135,000 km, greaterthan any other known minor-planet binary (<em><font color="#003399">7</font></em>). <font color="#ff0000">The separationis so large that this nearly equal-mass binary should be incrediblyfragile to dynamical disruption, and its continued existencein the middle of the main Kuiper Belt puts strong constraintson the history of the Belt</font> (<em><font color="#003399">8</font></em>).</p> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[xXTheOneRavenXx]

Is it possible that our closest neighbouring Centauri star system and whatever Oort cloud that may surround the binary or Proxima could possibly come in contact with or a large body within it have a gravitational affect on our Oort cloud? I know there is still 4.37 LY's between Alpha Centauri and our sun, and 4.2 LY's between Proxima and our sun... is there any shift in their orbits that would bring either of these stars close enough that any existing Oort cloud objects would affect ours? Just a thought instead of going out on a limb with an undiscovered companion of our own sun. <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Is it possible that our closest neighbouring Centauri star system and whatever Oort cloud that may surround the binary or Proxima could possibly come in contact with or a large body within it have a gravitational affect on our Oort cloud? I know there is still 4.37 LY's between Alpha Centauri and our sun, and 4.2 LY's between Proxima and our sun... is there any shift in their orbits that would bring either of these stars close enough that any existing Oort cloud objects would affect ours? Just a thought instead of going out on a limb with an undiscovered companion of our own sun. <br />Posted by xXTheOneRavenXx</DIV><br /><br />Not likely for the Centauri system. However other stars have come and will come closer to the sun than them, where such interaction may have been or will be possible. <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>

 

[3488]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'><font color="#ff0000">Not likely for the Centauri system. However other stars have come and will come closer to the sun than them, where such interaction may have been or will be possible. <br /> Posted by MeteorWayne</font></DIV></p><p><strong><font size="2">Hi Wayne, try Gliese 710. </font></strong></p><p><font size="2"><strong>I could imagine rogue planets etc, passing through the Oort Cloud causing some comets ti be disrupted, but this would not be periodic, more random events.&nbsp;</strong></font></p><p><font size="2"><strong>Thge interstellar medium in the spiral arms & / or on the galactic plane may be slightly denser, potentially causing some disruption, but I do not think Nemesis exists & as you correctly said an orbital period of 26 million years around our Sun would not be possible as the aphelion would be well outside the Sun's Hill Sphere, & could be snatched by Alpha Centauri, Sirius, Procyon, etc.</strong></font></p><p><font size="2"><strong>Andrew Brown. </strong></font></p> <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[silylene]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Is it possible that our closest neighbouring Centauri star system and whatever Oort cloud that may surround the binary or Proxima could possibly come in contact with or a large body within it have a gravitational affect on our Oort cloud? I know there is still 4.37 LY's between Alpha Centauri and our sun, and 4.2 LY's between Proxima and our sun... is there any shift in their orbits that would bring either of these stars close enough that any existing Oort cloud objects would affect ours? Just a thought instead of going out on a limb with an undiscovered companion of our own sun. <br />Posted by xXTheOneRavenXx</DIV><br /><br />If this putative close approach had occured within the last billion years or so, it&nbsp;should have disrupted the very delicate QW322 binary pair.&nbsp; Since QW322 was not disrupted, no other star has approached closely enough to create havoc at least with&nbsp;the with the&nbsp;extreme Kuiper&nbsp;belt. <div class="Discussion_UserSignature"> <p align="center"><font size="1">petet = <font color="#800000"><strong>silylene</strong></font></font></p><p align="center"><font size="1">Please, please give me my handle back !</font></p> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If this putative close approach had occured within the last billion years or so, it&nbsp;should have disrupted the very delicate QW322 binary pair.&nbsp; Since QW322 was not disrupted, no other star has approached closely enough to create havoc at least with&nbsp;the with the&nbsp;extreme Kuiper&nbsp;belt. <br />Posted by petet</DIV><br /><br /><strong><font face="Times New Roman" size="4"><font face="Times New Roman" size="4"><p align="left">Perturbation of the Oort Cloud by Close Stellar Approaches</p></font></font><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"><p align="left">J. Garcia- Sanchezl, P. R. Weissmanl, R. A. Prestonl, D. L. Jonesl,</p><p align="left">J.-F. Lestrade2, D. W. Latham3 and R. P. Stefanik3</p></font></font></strong><em><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"><p align="left">1Jet Propulsion Laboratory, Mail stop 183-601, 4800 Oak Grove Drive, Pasadena, CA</p><p align="left">91109 USA. E-mail pweissman@issac.jpl. nasa.gov</p><p align="left">2Observatoire de Meudon&ndash;Paris/CNRS, F-92195 Meudon, France. E-mail</p><p align="left">lestrade@obspm. jr</p><p align="left">3Harvard-Smithsonian Center jor Astrophysics, 60 Garden St., Cambridge, MA 0215&rsquo;8</p><p align="left">USA. E-mail latham@cfa.harvard, edu</p></font></font></em><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"><p align="left">We combined Hipparcos proper motion and parallax data for nearby stars with groundbased</p><p align="left">radial velocity measurements to find stars which may have passed (or will pass)</p><p align="left">close enough to perturb the Oort cloud. We find the number N of close stellar approaches</p><p align="left">within distance D from the Sun (in parsecs) is N = 4.2 D2 Myr&ndash;l, less than previously</p><p align="left">predicted values. This is the result of observational incompleteness in the Hipparcos data,</p><p align="left">which is complete to a visual magnitude of only N7.3- 9.0. Two stars, Gliese 710 and SAO</p><p align="left">128711, have predicted closest approach distafices <105 AU (0.5 pc), through the outer</p><p align="left">Oort cloud. The minimum distance for GL 710 is 71,000 AU, 1.36 Myr in the future.</p><p align="left">For SAO 128711 the values are 57,000 AU, 1.2 Myr in the past, though the uncertainties</p><p align="left">are quite large. Both stars are red dwarfs with masses of *0,4- 0.7 Solar Mass. The absence of</p><p align="left">major stellar perturbers in the recent past is consistent with an analysis of the semimajor</p><p align="left">axis distribution of the long-period comets by Weissman (1993) who determined that we</p><p align="left">are not currently in a cometary shower. Based on dynamical simulations, the closest</p><p>predicted stellar passages may result in an increased flux of Oort cloud comets of 50<strong><font face="Times New Roman" size="1"><font face="Times New Roman" size="1">%.</font></font></strong></p></font></font><p><strong><font face="Times New Roman" size="1"><font face="Times New Roman" size="1">http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/19368/1/98-0710.pdf</font></font></strong></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>

 

[silylene]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Perturbation of the Oort Cloud by Close Stellar ...Posted by MeteorWayne</DIV></p><p>The Oort cloud is further away than the extreme Kuiper belt.</p> <div class="Discussion_UserSignature"> <p align="center"><font size="1">petet = <font color="#800000"><strong>silylene</strong></font></font></p><p align="center"><font size="1">Please, please give me my handle back !</font></p> </div>