New type of tidal heating would mean much higher energy transfered to subglacial oceans of Europa, T

[h2ouniverse]

<p>From this article on new scientist:</p><p>&nbsp;http://www.newscientist.com/article/mg20026864.500-swirling-waters-boost-chance-of-life-on-europa.html</p><p>refering to this abstract:</p><p>http://www.nature.com/nature/journal/v456/n7223/abs/nature07571.html</p><p>What is especially interesting imho, beyond the consequences on the Europan iceshelf thickness, is that, if confirmed, could mean potentially more energy too in other systems that have even less "classical tidal coupling".</p><p>Ganymede? Callisto? Dione? Titan? Ariel? Umbriel? Charon? Hi'iaka?</p><p>&nbsp;Best regards.</p>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>From this article on new scientist:&nbsp;http://www.newscientist.com/article/mg20026864.500-swirling-waters-boost-chance-of-life-on-europa.htmlrefering to this abstract:http://www.nature.com/nature/journal/v456/n7223/abs/nature07571.htmlWhat is especially interesting imho, beyond the consequences on the Europan iceshelf thickness, is that, if confirmed, could mean potentially more energy too in other systems that have even less "classical tidal coupling".Ganymede? Callisto? Dione? Titan? Ariel? Umbriel? Charon? Hi'iaka?&nbsp;Best regards. <br />Posted by h2ouniverse</DIV><br /><br />Having just read the article in the Dec 11 Nature, what struck me was how small the obliquity value needs to be to cause this huge heating effect. As litte as 0.16 degrees of tilt relative to it's orbit around Jupiter is sufficient to create far more heat than the tidal shape changes due to eccentricity, which is all that had been previously considered.</p><p>Wow!</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>

 

[w_d_w]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Having just read the article in the Dec 11 Nature, what struck me was how small the obliquity value needs to be to cause this huge heating effect. As litte as 0.16 degrees of tilt relative to it's orbit around Jupiter is sufficient to create far more heat than the tidal shape changes due to eccentricity, which is all that had been previously considered.Wow! <br /> Posted by MeteorWayne</DIV></p><p>I've been looking at Europa lately from the WorldWide Telescope I mentioned in another post. My biggest problem with this report is the massive impact crater on the planet. These pictures:</p><p>http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=75187340&albumID=2583570&imageID=40943417</p><p>http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=75187340&albumID=2583570&imageID=40943411</p><p>show the moon has a crater large enough to cause massive damage to the ice shell itself. I'm not a mathematician, so I can't say if the numbers are there, but wouldn't a shell thin enough to transfer chemicals be too thin to sustain an impact of that size?</p><p>Will </p>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Having just read the article in the Dec 11 Nature, what struck me was how small the obliquity value needs to be to cause this huge heating effect. As litte as 0.16 degrees of tilt relative to it's orbit around Jupiter is sufficient to create far more heat than the tidal shape changes due to eccentricity, which is all that had been previously considered.Wow! <br /> Posted by MeteorWayne</DIV></p><p>That's really interesting info.&nbsp;&nbsp; Hmm.&nbsp; The surface cracks certainly do seem to suggest a partial melting/cracking process is in play.&nbsp; I wonder if the surface would then also be heavily influenced by the "active" phases of the sun, and less affected during the quiet phases (like now). </p><p>&nbsp;</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>

 

[michaelmozina]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I've been looking at Europa lately from the WorldWide Telescope I mentioned in another post. My biggest problem with this report is the massive impact crater on the planet. These pictures:http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=75187340&albumID=2583570&imageID=40943417http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=75187340&albumID=2583570&imageID=40943411show the moon has a crater large enough to cause massive damage to the ice shell itself. I'm not a mathematician, so I can't say if the numbers are there, but wouldn't a shell thin enough to transfer chemicals be too thin to sustain an impact of that size?Will <br /> Posted by w_d_w</DIV></p><p>I can't help but wonder from that image is the impacting object didn't simply penetrate through the ice.&nbsp; I guess we'd need to understand something about the topology of that crater.&nbsp; I think the transfer of energy would also depend not only on the thickness of the ice, but the depth of the water, and the density of the material under the water.&nbsp;&nbsp; A lot of factors would come into play depending on the size of the object, and the speed of the object at impact. </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>

 

[franontanaya]

<p>Edit: Ew, I didn't read the post above. </p><p>Or perhaps the crust was so thin that the meteor just punched a hole through it. The falling debris and refrozen vapor could have buried other damages.</p> <div class="Discussion_UserSignature"> </div>

 

[3488]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'><font color="#ff0000">I've been looking at Europa lately from the WorldWide Telescope I mentioned in another post. My biggest problem with this report is the massive impact crater on the planet. These pictures:http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=75187340&albumID=2583570&imageID=40943417http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=75187340&albumID=2583570&imageID=40943411show the moon has a crater large enough to cause massive damage to the ice shell itself. I'm not a mathematician, so I can't say if the numbers are there, but wouldn't a shell thin enough to transfer chemicals be too thin to sustain an impact of that size?Will <br /> Posted by w_d_w</font></DIV></p><p><font size="2"><strong>Europa's ice crust is of varying thicknesses for sure. In some places, many KM thick, being able to support largeish impact craters, in others thin enough to display tilted bergs, etc. </strong></font></p><p><font size="2"><strong>Remember everyone, subsurface ocean on Europa is not proven fact & may not even exist at all. A lot of hype suggests its a done deal. It is not. There is some evidence to support a subsurface ocean for sure, but it could also be convecting 'warm ice' below a more brittle colder harder ice crust (1 Ceres may also show evidence for this, but will have to wait for DAWN's arrival).&nbsp;</strong></font></p><p><font size="2"><strong>I suspect that there IS some liquid H2O in places below Europa's ice crust.</strong></font></p><p><font size="2"><strong>There are likely to be volcanoes on the 'ocean' floor, as Europa is being kept warm by the same forces that power the violent eruptions on Europa's slightly larger & considerably more massive inner neighbour Io, but with Europa the flexing is only about 15% of Io's.&nbsp;</strong></font></p><p><font size="2"><strong>One area I suspect that there is subsurface liquid H2O is Conamara Chaos.</strong></font></p><p>&nbsp;<img src="http://sitelife.space.com/ver1.0/Content/images/store/8/2/f8e1f428-d840-4b03-b286-09649f7b2225.Medium.jpg" alt="" />&nbsp; <img src="http://sitelife.space.com/ver1.0/Content/images/store/12/0/2c16c5bc-a13f-4788-b0a9-91d70d95550d.Medium.jpg" alt="" /></p><p> <img src="http://sitelife.space.com/ver1.0/Content/images/store/13/4/8d6fcb56-6925-41b5-8462-b97c444dcbe3.Medium.jpg" alt="" /></p><p><font size="2"><strong>Ice blisters, diapirs??</strong></font><br />&nbsp;<img src="http://sitelife.space.com/ver1.0/Content/images/store/2/14/12742f22-ccc9-4e6c-8e73-7dc4b4c24338.Medium.jpg" alt="" /><br /><font size="2"><strong>However the below point to regions with a much thicker crust. </strong></font><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/9/4/69234810-064a-443e-842c-28e4f6ca236a.Medium.jpg" alt="" /></p><p><font size="2"><strong><br />Map showing Europa's ice fractures / tectonic failting.</strong></font><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/1/10/b1b7bf73-ee45-4993-ba34-fa2ffd76e16c.Medium.jpg" alt="" /></p><p> </p><p><font size="2"><strong><br />Andrew Brown.&nbsp;&nbsp;</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>