Titan's topography, strange.... |
Titan's topography, strange.... |
Apr 12 2009, 12:44 PM
Post
#1
|
|
Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
Recent article in Science by Zebker et al.:
Zebker et al. Science in press, "Size and Shape of Saturn's Moon Titan". doi: 10.1126/science.1168905 (published online April 2, 2009) Link to abstract (pay-for article): http://www.sciencemag.org/cgi/content/abstract/1168905 Article on spaceref discusses this paper: http://www.spaceref.com/news/viewpr.html?pid=27912 Figure 3 from the Science article is a global elevation map relative to barycenter. Key points of article:
"Xanadu seems to be systematically lower than other parts of the equatorial belt, and not uplifted like most mountainous areas on Earth." (quote from Fig. 3 caption in article) -Mike -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
|
|
|
Oct 6 2009, 09:03 PM
Post
#2
|
|
Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
Interesting comparisons there for sure. I'd like to take the digital terrain model at the bottom right there as a starting point for comments, first of all on the elevations question. That model and another like it form the basis of the statement by Soderblom et al that the bright features within the dark plains are around 100m (not hundreds of metres) high. That particular example shows a feature I have been calling 'the enclosure' some few kilometres southwest of the landing site. An interesting fact about the enclosure is that its interior is higher than the plains around it. Also, in general plan it does not resemble at all what we might call the classical spooky dude shapes with upstream ovals and downstream points. For both of these reasons I think it is actually something intrinsically different. (Your terrestrial analog for that feature is maybe less convincing that your others, which wouldn't be surprising if it is not in fact a flow feature.) The other 3D model shows mainly part of the 'Huygens island' with only a small part of the dark plain. The beach-like features there are actually contiguous with the island and may indeed be structurally part of it. Therefore they too, in my view, are ruled out of the spooky dude club. This means that for the features under discussion we have in fact no elevation data. The dark oval closest to the landing site is about 500 meters wide. It's bright boundary is only tens of metres wide and cannot be more that a few metres high in most places. The wider parts of the 'spooky dude' nearer the pointy end may be a bit higher, or they may not.
I agree with your statement that nothing in the immediate vicinity of the probe seems likely to be bedrock. The VIMS observation should contain pixels entirely filled by spooky dude bright stuff. I expect them to be spectrally distinct from the highlands bright stuff of the Huygens island. EDIT - the 'enclosure' shows up quite clearly on SAR - I think it was one of the features used by Mike and yourself for the most recent attempts at precise registration of the DISR with SAR - whereas the dudes are barely if at all visible, consistent with relatively low relief. |
|
|
Lo-Fi Version | Time is now: 26th September 2024 - 09:11 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |