Rhea

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silylene old

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Cassini just did a very close pass to Rhea. WOW !!! Looks different than the other satellites when viewed closup. Oddly smooth and lumpy with heavily eroded craters all over...<br /><br />Find the raw closeup photo's here:<br />click here<br /><br />Here is a nice super closeup shot: http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS16/W00012123.jpg<br /><br />(See the original for details - so much got lost squeezing this photo down under the posting limits). <br /><br />(Edited to shorten link.) <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>
 
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harmonicaman

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This apparent weathering is likely due to Rhea collecting any material which happens to trespass into its niche in Saturn's rings.
 
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newtonian

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Silylene - I agree - Wow!<br /><br />This time frame for the 500 images confused me - to cut and paste:<br /><br />05/14/2004 00:00 through 12/31/2010 23:59<br /><br />Did Casini-Huygens do time travel?<br /><br />How did they transmit images from 12/31/2010???????
 
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newtonian

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silylene - concerning this photo:<br /><br />http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=54854<br /><br />And also your posted photo:<br /><br />Are those bubbles? Reminds me of mud pots in Yellowstone and Lassen Volcanic National Parks - but frozen (motion stopped)!<br /><br />Previous to these photos the question of two different features of Rhea led to speculations of partial resurfacing. <br /><br />What's the latest on causes for what we see?<br /><br />Thank you for the links, btw.
 
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CalliArcale

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That is way cool. To me, it seems very different from what has been seen on Dione thus far. That's interesting, of course, because Dione and Rhea have long been thought similar. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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silylene old

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<font color="yellow">Are those bubbles? Reminds me of mud pots in Yellowstone and Lassen Volcanic National Parks - but frozen (motion stopped)! </font><br /><br />I think those are shallow degraded craters. Light from unexpected angles can play funny illusions on the eye and make a crater look like a bubble. (or am I wrong, and they are bubbles?) <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>
 
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bonzelite

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regions of it's surface look elastic, as if the impact craters, or whatever they are, happened upon some silly putty, and someone stretched it out. very bizarre. <br /><br />i'm continually blown away by the sheer diversity of strange surfaces and objects in the Saturnian mini-solar system. i just looked at more images as i'm editing this post. there is speak of bubbled terrain. and yes. it is that. like pimples. it is exactly that. domes everywhere. i can tell because of the light source and how it casts shadows on the relief of the terrain. <br /><br />i suppose this adds yet again to the mountain of newly created mysteries that exist at Saturn. this is incredible. <br /><br />
 
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newtonian

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bonzelite, sillylene - I'm bubbling over with curiosity!<br /><br />Possible causes if they are bubbles?<br /><br />Like, for example, heating followed by rapid and permanent cooling - there were previous models involving a resurfacing.<br /><br />Perhaps under surface heating as at Lassen and Yellowstone - perhaps by either tidal interaction, magnetic field interaction, internal heat from other sources including radioactivity, etc. [geothermal heat].<br /><br />What is the current surface temperature? I assume fairly cold.<br /><br />Is Rhea, like Jupiter and Saturn, radiating more heat than it receives from the sun (+ Saturn?).<br /><br />Does (or did) Rhea interact with Saturn's magnetic field?
 
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thechemist

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As silylene suggested, these are craters and not bubbles. It has to do with the human mind's perception of depth under certain lighting conditions. <br />I have fallen victim of that illusion myself numerous times.<br />Just by rotating the image 180o the bubbles are gone, and craters appear <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>
 
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bonzelite

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no. there are raised features there. pimples. <br /><br />there are craters, too. but there are also numerous dome-like features everywhere. <br />
 
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thechemist

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dome-like features ? <br />Can you please pinpoint them in the inverted image ? <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>
 
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jatslo

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The first time I looked I saw bubbles, and I see craters now; however, someone inverted the image in the last post, and now I am confused again: which one is real?
 
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Swampcat

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<font color="yellow">"which one is real?"</font><br /><br />They are both real. It's an example of how your perception can be fooled. Kinda like looking at a rock and seeing a flower or a bush. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <font size="3" color="#ff9900"><p><font size="1" color="#993300"><strong><em>------------------------------------------------------------------- </em></strong></font></p><p><font size="1" color="#993300"><strong><em>"I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."</em></strong></font></p><p><font size="1" color="#993300"><strong>Thomas Jefferson</strong></font></p></font> </div>
 
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jatslo

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You altered one in your computer; inverted the imagery or something, right?
 
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newtonian

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TheChemist - Are you serious? Inverted images causing depressions to appear as the opposite?<br /><br />Er, can you show me an inverted image of Mt. Everest that appears as a canyon?<br /><br />Or a picture of the moon with bubbles instead of craters?<br /><br />I'm not saying you are wrong. Just simply that it does not compute!
 
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thechemist

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<i>Newtonian - Are you serious? Inverted images causing depressions to appear as the opposite? </i><br /><br />I have to apologize for the confusion, the image I posted contains the original image to the left, and the same image rotated by 180o (upside down) to the right. The term "inverted" I used causes confusion, sorry.<br /><br />I am not saying that this happens to all orbiter images, only to images that have been obtained under certain lighting conditions, leading to craters looking like bubbles. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>
 
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Swampcat

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<font color="yellow">"You altered one in your computer; inverted the imagery or something, right?"</font><br /><br />I didn't do it. TheChemist did it.<br /><br />See his post above this one: <font color="orange">"I am not saying that this happens to all orbiter images, only to images that have been obtained under certain lighting conditions, leading to craters looking like bubbles."</font><br /><br />Anyone who has done a fair amount of image analysis will be fooled by this effect on occasion. It's a bit of an optical delusion, if you will. It happens because of the way your brain processes visual information. Accept it. It's a real effect. Nobody's pulling funny tricks on you. But it <b><i>is</i></b> why one should be cautious when assuming what they think they see is really what's there. <div class="Discussion_UserSignature"> <font size="3" color="#ff9900"><p><font size="1" color="#993300"><strong><em>------------------------------------------------------------------- </em></strong></font></p><p><font size="1" color="#993300"><strong><em>"I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."</em></strong></font></p><p><font size="1" color="#993300"><strong>Thomas Jefferson</strong></font></p></font> </div>
 
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thechemist

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And here is an example from the moon. It is the first image in this page :<br />http://www.hq.nasa.gov/office/pao/History/SP-362/ch5.1.htm<br /><br />I see bubbles on the left, craters on the right. Note that this illusion might not apply to<br />everyone, as far as I know, some people are able to see craters in both images, al'right ? <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>
 
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telfrow

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I learned that lesson at Mars Clickworkers. If you did enough images, you saw the effect quite a bit. <br /><br /><i>Edit:</i> And for anyone interested, the Clickworkers program is supposed to start again in 2006 with MRO images. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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telfrow

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See posts below... <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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telfrow

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<font color="yellow">Er, can you show me an inverted image of Mt. Everest that appears as a canyon?</font><br /><br />Here's something terrestrial. <br /><br />A hill? <br /><br />A lava dome?<br /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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telfrow

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Or Meteor Crater? <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>
 
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