Uranus Moons Miranda, Ariel, Umbriel, Titania & Oberon.

[3488]

This color composite of the Uranian satellite Miranda was taken by Voyager 2 on January 24, 1986, from a distance of 147,000 kilometers (91,000 miles). Miranda's regional geologic provinces show very well in this view of the southern hemisphere, imaged at a resolution of 2.7 kilometers (1.7 miles). The dark- and bright-banded region with its curvilinear traces covers about half of the image. Higher-resolution pictures taken later show many fault valleys and ridges parallel to these bands. Near the terminator (at right), another system of ridges and valleys abuts the banded terrain; many impact craters pockmark the surface in this region. The largest of these are about 30 kilometers (20 miles) in diameter; many more lie in the range of 5 to 10 kilometers (3 to 6 miles) in diameter. (Courtesy NASA/JPL) <br /><br /> <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]

Umbriel (again). I think that this is the best image that I can do. <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 have been able to find a Uranusshine image of Ariel on the PDC site & able to process it a bit myself.<br /><br />Clearly visible is one prominent fresh impact crater, two small ones & two tectonic canyons, <br />merging into one.<br /><br />All on the dark Winter hemisphere.<br /><br />Voyager 2.<br /><br />NASA / JPL.<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]

Ariel.<br /><br />Blow up & enhancement of the Uranus lit crater on Ariel's Winter nightside.<br /><br />Clearly visible is the general circular shape, a very bright ejecta blanket (suggesting a <br />very young crater as the ice is still clean) & what is may be a central peak.<br /><br />Not bad for data that is nearly 22 years old.<br /><br />Voyager 2. <br /><br />NASA / JPL. <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>

 

[vogon13]

Regarding possible elevation differences keyed to albedo variations, might we be seeing<br />something on Umbriel that is related to a possible process observed on Hyperion and Iapetus ??<br /><br />Low spots being darker ?? Sounds pretty familiar . . . <br /><br /><br /><br />I'm thinking N2/CH4 venting from Ariel has reached Umbriel and stained it.<br /><br />A demonstrably 'active' Ariel would be interesting . . . . <br /><br />{possible problem: temperature regime on Umbriel is quite a bit colder, not sure that a similar mechanism could be working here. Any chance reflected sunlight from Uranus might warm Umbriel a bit ?? Or perhaps charged particles trapped in magnetosphere can catalyze the darkening reaction in lieu of heat ?? }<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[signalhill]

It appears as if something rubbed or "slid" into home plate on Miranda, ie, the dark banding areas resemble skid marks. Something must have hit it at shallow angles. It must have been very violent.

 

[vogon13]

Sorry I don't have a link, but the 3D processed Miranda pictures don't show any coherent correlation between surface patterns and elevation.<br /><br />Miranda is just a mess.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[signalhill]

<br />I sure wish I could see those 3D images. Do you think you might be able to find them somewhere?<br /><br />I don't see any dark material on the floors of the craters on Miranda, I think there are different processes at work here.<br />

 

[vogon13]

It's the Miranda 'fly over' video. I see it on NASA TV once in a while. (anyone here savy with U-tube??)<br /><br />Despite my (excessive) willingness to theorize about Iapetus, I find Miranda to be inexplicable at this point. That's not to say inspiration won't strike at some point, but it hasn't since 1/26/1986.<br /><br /><br />Regarding NASA TV, the best way to find interesting stuff on it, is to just bite the bullet and TIVO 5 or 6 hours of it everyday, and then scan the recording at the highest speed your machine has.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[3488]

Maybe Oberon has rolled, like Saturn's Enceladus & Dione, & perhaps Oberon's <br />sibling Miranda too.<br /><br />Perhaps also Oberon is still active on a small scale. Is that crystalline ice deep or is a frost covering?<br /><br />Bearing in mind, average temperature on Oberon is approx minus 215 Celsius / 58 Kelvin<br />so is one of the coldest, larger objects in the solar system.<br /><br />Just a thought.<br /><br />Below. Oberon in approx true colour.<br /><br />Note the very dark floored craters, possible cryovolcanic flooding of these?<br /><br />Large crater near centre in MacBeth.<br /><br />Also note the lofty mountain at the Eight O Clock position. <br /><br />Further, closer inspection reveals this to be a central peak.<br /><br />Voyager 2<br /><br />NASA / JPL.<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>

 

[signalhill]

"That's not to say inspiration won't strike at some point, but it hasn't since 1/26/1986."<br /><br />What inspiration is that?

 

[brellis]

Challenger-wikipedia <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>

 

[vogon13]

My very first post at Spacedotcom was pretty much 'spot on' regarding what was up with Iapetus regarding an emplaced ring structure.<br /><br />I have been looking at pictures of Miranda since they were downlinked from Voyager II (coincidentally on the same day as the Challenger accident) and have never achieved any level of comprehension about what in the blue blazes happened to Miranda.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[signalhill]

Wouldn't you entertain the possibility that Miranda was struck by objects that have been vaporized and and taken into the body? The linear tracks are reminiscent of motion streaks.

 

[vogon13]

No easy correlation between surface texture, topography and albedo on Miranda.<br /><br />A couple of posts at SDC is not going to 'resolve' the Miranda problem, regardless of the amount of talent I apply to the problem.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[signalhill]

Yes this is only speculative discussion. So i will ask you again, would you entertain the idea that the dark streaks on Miranda are due to contact with a moving body or bodies? <br /><br />The linear streaking areas are directional and parallel. This appears due to movement. Would you concur?<br />

 

[vogon13]

No.<br /><br />The streaks do not correlate to topography.<br /><br />If I scrape something, the surface gets 'smoothed' off in that spot, the ups and downs of the Miranda terrain is totally uncorrelated with the streaking.<br /><br />It's a mighty weird object.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[signalhill]

Would it be plausible that the streaks are ancient and the land deformed or undulated after they were created?<br /><br />

 

[3488]

One idea BTW is that the 'Coronae' on Miranda are the results of former Co-orbitals impacting<br />at low speed.<br /><br />The positions of the 'Coronae' support just such a scenario, plus the fact<br />the heavily cratered, unevolved areas also seem to be positioned correclty to support that & that <br />the transition between the two <br />is quite sudden, no outer concentic rings, like Valhalla on Callisto (which almost certainly <br />was due to a high speed impact).<br /><br />Below Miranda, transition from ancient cratered terrain to 'Coronae'.<br /><br />Voyager 2.<br /><br />NASA / JPL.<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>

 

[CalliArcale]

Miranda is one of my favorite solar system bodies because it's just so weird. Right up there with Io, Europa, Iapetus, Enceladus, Titan, and Triton. This is one of the reasons I'm much more fascinated by the outer solar system than the inner. It's all of these weird moons.<br /><br />Charon's another oddball, I suspect, so New Horizons should be very interesting indeed.<br /><br />I wish there were a Uranus-orbiter in the planning stage. I've heard of a Neptune Orbiter; that's slightly less complicated, but still so expensive it's got an uphill battle to get approved. Has anybody heard of anything like that? Some of you guys seem to be pretty well connected in planetary science. <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>

 

[h2ouniverse]

The biggest hurdle is the mastery of the aerobraking. This being said it's a matter of will...<br /><br />I share your fascination for the outer system, and the frustration that so much is spent on Mercury missions by NASA, ESA, JAXA. Venus express was not so much expensive. But Messenger and BepiColombo are.<br /><br />We should also count Ceres as an outer system object(another icy world). And now new interesting dwarves in KB. Another incitation to go outwards.<br /><br />Best regards.