Post Block Island Meteor Studies (The Western Route), The 6th Leg in our Zig Zag Journey to Endeavour Crater Options

[jamescanvin]

Recent Drive Direction mosaics:

2006


2007


2009


All images link to the same page.

James

[HughFromAlice]

Really nice !!!

[phase4]

Absolutely delicious. Thank you!

[dburt]

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

[Ant103]

Very nice views James

Here is the Navcam view of Sol 2011 showing the Nereus -- Nautilus crater. Anaglyph view at the right (Stu, if you read me )

[Nirgal]

Recent Drive Direction mosaics:

Excellent work !

The 2007 view in particular is phantastic (one of the best meridiani vistas so far)

[Guest_Oersted_*]

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!

[Guest_PhilCo126_*]

Oppy's tracks in those (superb) mosaics really look like driving ontop of very wet sand... or wet clay

[Tesheiner]

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

[jamescanvin]

Thanks for all the nice comments. Here is a quick go at the sol 2011 drive direction mosaic.



James

[dburt]

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

[serpens]

Oppy's tracks in those (superb) mosaics really look like driving ontop of very wet sand... or wet clay

Actually the tracks don't look significantly different to the Apollo rover tracks.

[Phil Stooke]

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

[Tesheiner]

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

[dburt]

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