Dawn Survey Orbit Phase, First orbital phase |
Dawn Survey Orbit Phase, First orbital phase |
Aug 4 2011, 11:37 PM
Post
#256
|
|
Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Anyone care to speculate on that long curved dark scar crossing a bunch of the left had side of the image? It looks like a flow of some sort to me. Post-impact volcanism? (by impact, I mean the little guy which seems to be the "source" of the digitate flows, or maybe that is the end of a flow....) -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
|
|
Aug 4 2011, 11:39 PM
Post
#257
|
|
Member Group: Members Posts: 796 Joined: 27-February 08 From: Heart of Europe Member No.: 4057 |
Any idea of what we are looking at? northern or southern hemisphere? it would be nice if the release had some context, not just the picture... Quick reprojection using one global image from HD animation (thanks Emily for images and Dawn team for animation!). -------------------- |
|
|
Aug 4 2011, 11:53 PM
Post
#258
|
|
Member Group: Members Posts: 714 Joined: 3-January 08 Member No.: 3995 |
Anyone care to speculate on that long curved dark scar crossing a bunch of the left had side of the image? First, part of it seems to be draped over a crater, so it probably settled down from above. Second, it seems to originate at that crater (or whatever) on the bottom. Is the curviness of the dark streak real, or is it due to the viewing angle of an irregular surface? |
|
|
Aug 5 2011, 12:02 AM
Post
#259
|
|
Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
There is something very unusual about that "flow" if that is what it is. If it were molten rock (or liquid of any kind) it would necessarily follow the contours of that last crater it crosses; either pool up in the bottom of it, or if the crater is on a slope then the flow would follow a circular path along the crater's wall. Instead it looks as though this dark feature was draped across the body from above like strands of hair or a veil. It has to have been deposited from above -- something like dust or fine particles continuously ejected downrange from it's source.
(enlarged and contrast enhanced crop) -------------------- If Occam had heard my theory, things would be very different now.
|
|
|
Aug 5 2011, 12:23 AM
Post
#260
|
|
Junior Member Group: Members Posts: 35 Joined: 10-July 11 Member No.: 6055 |
Yeah I was thinking that too, otherwise it flowed "uphill" and out of some of those craters. -kap |
|
|
Aug 5 2011, 12:39 AM
Post
#261
|
|
IMG to PNG GOD Group: Moderator Posts: 2250 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
Here is a first try from the rotation movie. Wow, this looks extremely interesting and nice. I'm planning to do a 3D model of Vesta by running stereo imagery through my stereo processing software but doubt I'll be doing it until the data is released at the PDS so I was disappointed to see that apparently that's not going to happen until about 18 months from now. As a matter of curiosity, how did you create this 3D model? It looks remarkably detailed keeping in mind limitations in the source data (no viewing geometry information etc.). |
|
|
Aug 5 2011, 01:27 AM
Post
#262
|
|
Member Group: Members Posts: 714 Joined: 3-January 08 Member No.: 3995 |
Another interpretation:
The "flow" could be a chance alignment of dark rays from two separate craters, and some topographic grooves. In the image, [attachment=25094:2_craters.PNG] purple shows rays from the larger crater, green shows rays from the smaller crater, and orange is interpreted as part of a system of linear valleys, some of which can be seen extending beyond the "flow" zone. Pink shows what could be rays from either crater. The dark stuff in the troughs could be exposed darker material, or the albedo effect of differing grain sizes, as could be the case with the features in the SP basin. On the previously release full-frame image, the prominent dark crater also has some dark rays: [attachment=25092:Dark_crater.PNG] |
|
|
Aug 5 2011, 01:38 AM
Post
#263
|
||
Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
Whoo-hoo! The July 31 image almost perfectly matches up to the filtered false-color image released as PIA14325.
Here is a blink animation between the two (I had to warp PIA14325: [Animated GIF: Click to animate] The dark albedo area corresponds to the dark blue streak. It begins at a splat that is likely yellowish white like it's neighbors. And look at those other splatty features as well! The large flat-floored crater at the upper right ("Brachiopod Crater") that has a small indent from another impact is pretty distinctive in the global map mosaic and other images of Vesta. I've been using that as a identification feature. It is pretty average looking in the false-color spectra. But look at the detail around the large crater south of it. WOW! Lotsa different stuff. Also note that the grooves do not show up in the false color image. They blend with the "average terrain" (constraining the ring hypotheses). [Corrected based on comments from Pablo below] -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
|
|
|
||
Aug 5 2011, 02:03 AM
Post
#264
|
|
Junior Member Group: Members Posts: 50 Joined: 27-June 11 From: Katlenburg-Lindau, Lower Saxony, Germany Member No.: 6038 |
Whoo-hoo! The July 31 image almost perfectly matches up to the VIR false-color image released as PIA14325. Just a precision, the PIA14325 is a color composite of three filters of the Framing Camera. No offense for VIR, they are remarkable in many aspects, but this image is not a product of theirs. -------------------- |
|
|
Aug 5 2011, 02:08 AM
Post
#265
|
||
Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
Static image, detail enhanced in colorized region using multiple HiPass filters, also contrast regionally contrast-adjusted:
-------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
|
|
|
||
Aug 5 2011, 05:20 AM
Post
#266
|
|
Member Group: Members Posts: 106 Joined: 26-September 05 Member No.: 508 |
As a matter of curiosity, how did you create this 3D model? It looks remarkably detailed keeping in mind limitations in the source data (no viewing geometry information etc.). It was made from the rotation movie by first tracking the camera and creating the viewing geometry. Then a point cloud was generated and it was filtered and turned into a Poisson mesh. As you say there is not any viewing geometry data yet and this seems to be the only way to get a decent model. However mapping will be more tricky, I will try to fix the pole & equator from the published map. |
|
|
Aug 5 2011, 06:21 AM
Post
#267
|
|
The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
Here is a first try from the rotation movie. Wow, that's pretty amazing stuff! I have no idea whatsoever how you computer warlocks generate things like that, but I'm very glad you can! -------------------- |
|
|
Aug 5 2011, 06:22 AM
Post
#268
|
|
Junior Member Group: Members Posts: 66 Joined: 26-May 06 Member No.: 790 |
|
|
|
Aug 5 2011, 09:24 AM
Post
#269
|
|
Member Group: Members Posts: 293 Joined: 22-September 08 From: Spain Member No.: 4350 |
|
|
|
Aug 5 2011, 09:29 AM
Post
#270
|
|
Lord Of The Uranian Rings Group: Members Posts: 798 Joined: 18-July 05 From: Plymouth, UK Member No.: 437 |
Here's my interpretation of the rotation movie. (Thanks Emily for the frames!) The frame rate interpolation isn't as smooth as Tayfun's, unfortunately:
http://youtu.be/eBHgcTxhG-Y?hd=1 -------------------- |
|
|
Lo-Fi Version | Time is now: 26th April 2024 - 07:35 PM |
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. |