Goodbye Purgatory Dune!, Oppy on the move |
Goodbye Purgatory Dune!, Oppy on the move |
Jul 1 2005, 09:08 AM
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#1
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Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
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Jul 1 2005, 09:57 AM
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#2
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Newbie Group: Members Posts: 14 Joined: 20-April 05 From: Finland Member No.: 275 |
I really hope so. Maybe we see Victoria before Christmas.
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Jul 1 2005, 10:05 AM
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#3
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
Goodbye Purgatory..we barely knew ye...
well, actually, we've gotten to know ye quite well Doug |
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Jul 1 2005, 12:07 PM
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#4
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
We got to know ye better than I ever wanted to!
-the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Jul 1 2005, 12:20 PM
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#5
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Member Group: Members Posts: 221 Joined: 25-March 05 Member No.: 217 |
It's good to be moving again. As I'm mostly an onlooker I look forward to seeing who will be first to show the point on the route where Oppy will stop driving north and turn back toward the south. Will it be east or west first my guess north then west then south.
Thanks to all the forum contributions. Reckless |
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Jul 1 2005, 01:02 PM
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#6
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Member Group: Members Posts: 753 Joined: 23-October 04 From: Greensboro, NC USA Member No.: 103 |
I'll have to admit that I was skeptical that there was anything different about the makeup of Purgatory Dune when Oppy first got stuck there. In the image Tesheiner posted above, I'm amazed to see that Oppy dug in quite far into the dune surface even when it was positioning itself for its investigations over the past week. That is a MIGHTY soft dune!
-------------------- Jonathan Ward
Manning the LCC at http://www.apollolaunchcontrol.com |
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Jul 1 2005, 01:35 PM
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#7
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
I feel it is a sensate decision not to adventure going toward south unless its traction capability is improved as the required for that zone without any other help and also as remote robot. I know it is very brave to transverse thru chopped dunes. Hope that the team will get greater information about the land and trace the safest and easiet route toward to Erberus or Victoria????
Rodolfo |
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Jul 1 2005, 02:02 PM
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#8
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Senior Member Group: Members Posts: 2872 Joined: 22-April 05 From: Ridderkerk, Netherlands Member No.: 353 |
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Jul 1 2005, 02:07 PM
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#9
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Senior Member Group: Members Posts: 2872 Joined: 22-April 05 From: Ridderkerk, Netherlands Member No.: 353 |
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Jul 1 2005, 02:32 PM
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Member Group: Members Posts: 154 Joined: 8-June 04 Member No.: 80 |
QUOTE (Tesheiner @ Jul 1 2005, 09:08 AM) Glad to know we're back |
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Jul 5 2005, 12:45 PM
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#11
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Senior Member Group: Members Posts: 3008 Joined: 30-October 04 Member No.: 105 |
QUOTE Panorama wheeltracks at the rear of Opportunity at Purgatory Dune. And we're already starting to get downwind tails from the recent wheeltracks. These are potentially active dunes! --Bill -------------------- |
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Jul 5 2005, 12:55 PM
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#12
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Member Group: Members Posts: 290 Joined: 26-March 04 From: Edam, The Netherlands Member No.: 65 |
QUOTE (Bill Harris @ Jul 5 2005, 12:45 PM) And we're already starting to get downwind tails from the recent wheeltracks. These are potentially active dunes! --Bill Only if the "pavement" is broken I'd say. Then the fines underneath are exposed and free to go. My feeling says that the winds on Mars don't carry enough energy to break apart the upper layer. I wonder for how long this situation has been that way. And (even more intersting to know): What process is responsible for this tough upper layer ? Liberation of chemically bond water by intense and long UV-exposure, on it's turn cementing together the minerals ? |
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Jul 5 2005, 02:40 PM
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#13
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
I put my comments, I have seen a fine sand cementing cap on the desert. This cementing strate is very fragil. Once it is pressed, it cracks very easy. This case was caused by evaporating wet sand. This is only valid for a short time that is not the case for Mars that the water might probably have gone completely after 1.2 Billones years since its conception.
Rodolfo |
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Guest_BruceMoomaw_* |
Jul 5 2005, 03:56 PM
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Guests |
Actually, we've seen a surface crust on Mars' soil virtually everywhere we've landed -- the Vikings saw it clearly. It seems be a salt crust left behind by very small traces of surface liquid water left behind in the upper surface soil seasonally (along with some more dramatic moistening at intervals of a few tens of thousands of years as Mars' axial tilt changes and water ice thus migrates back and forth between the planet's polar and equatorial regions). It certainly doesn't ever require the existence of large amounts of liquid water on the surface at any time.
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Jul 5 2005, 05:46 PM
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#15
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Senior Member Group: Members Posts: 3008 Joined: 30-October 04 Member No.: 105 |
That is why I sail "potentially" active dunes. With the desert pavment/duricrust/"cementicrust" on the dunes it may take milennia for them to move. But we see here that the atmosphere can and does have the ability to move fine surface dust on a daily and routine basis. Oppy is not in the midst of a windstorm and the dust from the wheeltrack disturbance is rapidly moving in s short time.
In another thought, even though the density of the Martian atmosphere is very low and cannot move heavier particles like blueberries, it might happen that during dust storms and high wind velocity events, the wind can pick up sediment as a bedload and the density of the wind+bedload might be high enough to move heavier particles and thereby move dunes. There is a lot to learn here. --Bill -------------------- |
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