Enceladus, the Europa of Saturn

[h2ouniverse]

The presentations I could attend on April 19th at EGU were mainly dealing with Titan and Enceladus, and based on recent Cassini's observations, and/or recent modelling. I saw none of them still considering that Enceladus is not differentiated (silicates and H2O always separated, whether H2O is all ice or water+ice). <br />By the way, Callisto is assumed not differentiated (in core) AND with a liquid layer not too far from surface. But in the case of tiny Enceladus, that would really be strange since gravity is too low to form hot ice and core cannot be colder than outer layers. <br />Are there still skeptics of hydro- or cryo-activity deep inside Enceladus?

 

[h2ouniverse]

Sorry Borman. "Skeptics" is not an insult for me either. I fully agree on the compulsory character of doubt. Concerrning icy bodies, the norm these times is that theories are quickly upset. I would object however that the burden of proof is on the theorists with the less simple assumptions. Before getting observational evidence of Enceladus plume, this was on the shoulders of tenants of hydro/cryo activity. Now, it is on the ones of tenants of the less obvious theory. Theories should always be allowed to compete. It is like a running race, that is never won until finish line is crossed, but with undisputable intermediate rankings. And water-team leads.

 

[h2ouniverse]

And many bounce on other's ideas by the way. I think we agree. Your statement fits my view about communication-generated information.<br />This being said I would be hypocritical if I pretended to be neutral on issue of water in outer system bodies (as my alias suggests). So maybe I remember just what I wanted to hear. The point is to keep a prudent optimism in such heart-warming situations.<br />I really got the impression of a dominance of pro-water theories.<br /><br />Is proof of water water-proof? <img src="/images/icons/wink.gif" />

 

[brellis]

NASA Article <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

great!

 

[h2ouniverse]

Bacteria are so versatile!<br /><br />Extremophiles record:<br />* up to 113°C<br />* down to -18°C (metabolizing), far less in dormant state<br />* down to pH 0<br />* up to pH 11<br />* without Sun<br />* up to 1.5 Megarads<br />* in salty waters up to salt saturation<br />* in Chernobyl nuclear reactor<br />* up to 1000 bars<br />* close to vacuum<br /><br />What would be interesting would be to see whether some can live in water with 32% ammonia (the natural peritectic point, that shoud be very common in mid and outer solar system).<br /><br />Best regards.

 

[h2ouniverse]

Let's see with Cassini's fly by next year. Or with TANDEM if and when it arrives there (in two decades...)

 

[h2ouniverse]

Btw Borman,<br /><br />Are you speaking of molecular nitrogen or atom?<br />

 

[brellis]

Plumbing the plumes <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[brellis]

I get thirsty just reading this! (From the above article<br /><font color="yellow">Scientists have studied the plume dynamics since 2005, collecting data from several Cassini remote sensing instruments and those that sample particles directly, like the Cosmic Dust Analyzer. They conclude that an internal lake at a temperature of about 273 Kelvin (32 degrees Fahrenheit) is the best way to account for the material jetting out of the geysers. <br /><br />The next Enceladus flyby is in March 2008. The spacecraft closest approach will be at a mere 50 kilometers (30 miles) from the surface and the altitude will increase to about 200 kilometers (124 miles) as the spacecraft passes through the plumes. Cassini will sample the plumes directly and find out more about their makeup.</font>/safety_wrapper> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[h2ouniverse]

Does anyone know whether the March '08 fly-by can bring MAG measurements?<br />(for hint of a potential subsurface liquid)<br />

 

[3488]

Hi Joel, <br /><br />A huge big yes <img src="/images/icons/laugh.gif" /><br /><br />This was one of the primary reasons for the exceptionally close encounter.<br /><br />Hopefully the ISS will be used in narrow angle camera mode, until images are expected to blur<br />significantly, but the MAG measurements will be carried out right through closest approach<br />to Enceladus.<br /><br />The MAG & image data, may be enough, but I am not sure, if only a lander will answer <br />that fundamental question.<br /><br />Andrew Brown. <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>

 

[3488]

I wonder too borman, if it is due to the faults in the Tiger Stripes rubbing against <br />each other, creating the excess warmth that drives the geysers?<br /><br />Also how frictional heat will dissipitate beween the ice layer & a silicate core. if is exists?<br /><br />Clearly there is 'soft ice' at play here, but whether or not there is a subsurface ocean<br />is open to considerable doubt. Yes the evidence for a subsurface ocean at Europa is much <br />stronger, but even then it is<br />not a proven scientific fact, less so with Enceladus.<br /><br />I think the MAG observations at such close quarters in March, will still give a more definate<br />reading of the near Enceladus space environment.<br /><br />Andrew Brown. <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>

 

[brellis]

Lecture March 20, 2008 <br /><font color="yellow"> <br />Only two moons in our solar system are thought to have liquid water, and evidence collected by the Cassini spacecraft during multiple flybys suggests that Saturn's moon, Enceladus, could have liquid water reservoirs that erupt in Yellowstone-like geysers. Cassini has collected data, including high-resolution images of Enceladus' warm, south polar region, which reveal icy jets and towering plumes of particles and vapor ejected at high speed. Warm, low-density material rising to the surface could have literally caused Enceladus to roll over, putting the mass of warm material at the south pole. Tidal forces that squeeze and stretch the moon are a likely source of internal heat, but imaging and compositional data from the closest flyby yet of this intriguing satellite, earlier this month, may provide even more clues. We explore the mysteries of the fascinating world of Enceladus and investigate its place in the Saturn system.</font>/safety_wrapper> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[3488]

Thanks Brad. Is anyone from here going?<br /><br />Andrew Brown. <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>