Post Block Island Meteor Studies (The Western Route), The 6th Leg in our Zig Zag Journey to Endeavour Crater |
Post Block Island Meteor Studies (The Western Route), The 6th Leg in our Zig Zag Journey to Endeavour Crater |
Sep 21 2009, 07:36 PM
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#46
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
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Sep 21 2009, 08:06 PM
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#47
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Member Group: Members Posts: 237 Joined: 22-December 07 From: Alice Springs, N.T. Australia Member No.: 3989 |
Really nice !!!
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Sep 21 2009, 10:07 PM
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#48
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Junior Member Group: Members Posts: 95 Joined: 11-January 07 From: Amsterdam Member No.: 1584 |
Absolutely delicious. Thank you!
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Sep 22 2009, 01:16 AM
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#49
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Member Group: Members Posts: 384 Joined: 4-January 07 Member No.: 1555 |
The rocks look like they are full of blueberries. I wish they could take a closer look at those layered rocks. Agree completely, and congratulations to the posters of the panoramas. "Berry nice" views of abundant spherules in the dug-up boulders! As usual, but not usually so clearly seen in images, the spherules are strictly size limited, not clumped together, and occur along (are apparently controlled by) bedding planes. Well worth a closer look, because these features are NOT typical of sedimentary concretions. -- HDP Don |
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Sep 22 2009, 02:49 PM
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#50
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Senior Member Group: Members Posts: 1619 Joined: 12-February 06 From: Bergerac - FR Member No.: 678 |
Very nice views James
Here is the Navcam view of Sol 2011 showing the -------------------- |
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Sep 22 2009, 03:05 PM
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#51
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Member Group: Members Posts: 713 Joined: 30-March 05 Member No.: 223 |
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Guest_Oersted_* |
Sep 22 2009, 04:32 PM
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#52
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Guests |
Oh, but the undulating tracks in "2006".... - Lovely! She's really chugging along over the waves like a little fishing-boat off the Grand Banks!
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Guest_PhilCo126_* |
Sep 22 2009, 04:48 PM
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#53
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Guests |
Oppy's tracks in those (superb) mosaics really look like driving ontop of very wet sand... or wet clay
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Sep 22 2009, 07:30 PM
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#54
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Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
Here is the Navcam view of Sol 2011 showing the Nereus crater. Good job. I tried that one with autostitch but the results were only regular. One comment / correction: That mosaic was taken "mid-drive" during sol 2011 and the crater is not Nereus but actually Nautilus. A similar mosaic was also shot at the same position but with the pancam. 02011::p1713::03::6::0::0::6::0::12::navcam_3x1_az_198_3_bpp 02011::p2411::20::36::0::0::36::2::74::pancam_Nautilus_9x1_L257R2 |
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Sep 22 2009, 08:16 PM
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#55
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Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
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Sep 22 2009, 11:16 PM
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#56
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Member Group: Members Posts: 384 Joined: 4-January 07 Member No.: 1555 |
Oppy's tracks in those (superb) mosaics really look like driving ontop of very wet sand... or wet clay Agreed and a good observation. As has been noted previously, the apparent particle cohesion is most likely caused by a high content of salts that have sucked enough moisture out of their environment to render them sticky. Low temperatures favor the accumulation of moisture by hygroscopic or deliquescent salts. Wicking and evaporation of condensed moisture towards the surface could increase the salt content there (the duricrust hypothesis that dates from Viking lander days). The surface looks "wet" when it is actually salty, cold, and just a tiny bit moist (owing to the salts). Or at least that's one explanation. -- HDP Don |
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Sep 23 2009, 04:40 AM
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#57
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Senior Member Group: Members Posts: 1043 Joined: 17-February 09 Member No.: 4605 |
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Sep 23 2009, 11:19 AM
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#58
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Solar System Cartographer Group: Members Posts: 10153 Joined: 5-April 05 From: Canada Member No.: 227 |
Any stickiness would result in the wheels getting thickly coated with the damp regolith. It would be apparent immediately, and would have become a major problem from sol 1 on. The tracks look much more like impressions in fine dry powder - like lunar tracks as serpens said. But it's the behavior of the dust on the wheels that clinch it - it cakes on and then falls off, it doesn't really stick.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Sep 23 2009, 08:02 PM
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#59
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Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
Today, sol 2014, was once again dedicated for driving. About 60m were added to the odometer.
Here's a snapshot from Google Mars with our current position, based only in the mobility data while today's images don't hit the exploratorium. Opportunity is about 100m (two driving sols) from reaching a very big patch of bedrock which will probably be our "yellow brick road" for the next month or so. Check the KML file in the route map thread and don't forget to download SFJCody's map extensions to see the background map to the west. Edit: added a link to the map extensions. This post has been edited by Tesheiner: Sep 24 2009, 03:28 PM |
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Sep 24 2009, 12:38 AM
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#60
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Member Group: Members Posts: 384 Joined: 4-January 07 Member No.: 1555 |
Any stickiness would result in the wheels getting thickly coated with the damp regolith. It would be apparent immediately, and would have become a major problem from sol 1 on. The tracks look much more like impressions in fine dry powder - like lunar tracks as serpens said. But it's the behavior of the dust on the wheels that clinch it - it cakes on and then falls off, it doesn't really stick. Phil and Serpens - Thanks for your insights. Your logic apears excellent, although "damp" might be completely the wrong word here (i.e., for a molecule-scale coating of polar water molecules on top of unsatisfied ionic bonds), and weak self-adhesion of dust particles, allowing the development of "wet-appearing" vertical walls in ruts, isn't the same as strong bulk adhesion to a vibrating foreign object such as a moving wheel. Utter lack of personal experience dealing with martian conditions (very fine cold heterogeneous salty dust in a near vacuum in a weak gravity field) may have led me, and possibly you also, astray. Terrestrial experience (thick, moist, warm atmosphere, little day-night temperature difference, clay-dominated dust particles or rounded quartz sand, few salts, strong gravity field) could be misleading in dealing with Martian conditions. Lunar experience (perfect vacuum; hot dry angular salt-free glassy agglutinate particles) could also be misleading in this regard. Bottom line: I don't know who is right, possibly none of us, but I'd be wary of either terrestrial or lunar analogs. -- HDP Don |
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