29-30 August 2007 Icy Satellites (rev 49), Last stop on the road to Iapetus Options

[nprev]

Sorry for the confusion, you guys; let me try posting a clarification. If this works, I'm talking about the circled area, though the "dark spot" may be a semi-shadowed crater; the phase angle's pretty high:

[Guest_AlexBlackwell_*]

Sorry for the confusion, you guys; let me try posting a clarification. If this works, I'm talking about the circled area, though the "dark spot" may be a semi-shadowed crater; the phase angle's pretty high:

Maybe if you drew an arrow to the features, that would help. All I see are craters. And more craters.

What is interesting, at least to me, is the lighter-toned substrate exposed by impact gardening and/or downslope movement on crater walls. We've see this on other satellites.

[nprev]

Okay. Yeah, the light-toned substrate is the "albedo feature" I referred to, and here's that silly dark spot (which I'm now convinced is merely a shallow crater):




Sorry for the tempest in a teapot...(we need an embarrassment emoticon, here...)

[Bjorn Jonsson]

Some of the Rhea images are starting to show up on the JPL raw images page, including a beautiful WA set with Saturn in the background.

[elakdawalla]

Nice! My quick'n'dirty versions of the first three sets...



--Emily

[MarcF]

Not just craters on Rhea:

http://saturn.jpl.nasa.gov/multimedia/imag...3/N00090796.jpg

Crater chain or tectonic feature ?


Marc.

[dvandorn]

I've been saying for many, many months that Rhea exhibits more crater chains than I've ever seen on any other body in the Solar System. It has led me to speculate, here in this very forum, as to whether these chains are controlled exogenically (i.e., actual impact crater chains) or endogenically (i.e., tectonic features/fractures).

Note that the feature you linked to has a very small accompanying feature to the right and below (as this image is oriented). That much smaller feature is parallel to the larger feature. To me, that argues for endogenic control of these features.

I think that the rather large population of such chain features makes Rhea a lot more interesting than most everyone else here thinks.

-the other Doug

[volcanopele]

Highest resolution observations of Odysseus impact basin on Tethys:

http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=124822
http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=124817

[Gsnorgathon]

That first one almost looks like it's got a rille or two in it, though I'm guessing it's just some fortuitous shadows.

[elakdawalla]

Jason, I've seen this explained before but I keep forgetting the explanation. Can you explain the origin of the every-other-line truncation that appears in Cassini images that have lots of detail?

I love the sharp peaky shadows cast by the peak ring of Odysseus.

--Emily

[Bjorn Jonsson]

A long and narrow crater chain (?) on Rhea:

http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=124693

Rhea sure has a lot of these features.

[Big_Gazza]

Are any of the commercial photo packages (like Adobe) able to interpolate and fill in the truncated lines? eg by averaging the surrounding pixels?

[Ian R]

Here are the two Odysseus money-shots with the interlacing removed:





Ian.

[Ian R]

Nice! My quick'n'dirty versions of the first three sets...

Awesome composites, Emily!

[nprev]

Getting back on the horse after it threw me, as it were...(and if I'm being a complete clown, please somebody tell me so!!!)

Nice indeed, Emily!

Anyone else struck by the fact that the NW rim of Oydessus is practically worn into the landscape to the degree that it's virtually indistinguishable from the surrounding terrain? Means it's very old of course, but why just here? Was the impact a sort of glancing blow (i.e., oblique?), or did some sort of internal activity erase this portion of the rim, as well as a small segment in the SE quadrant?