[X] My Assistant

[Stu]

Well, what does everyone think of our long-awaited first view..?

[ElkGroveDan]

Yes - it's a long way off - and the balance will probably have shifted to the 'risk it' side of the scale compared to Endurance

I recall that was the attitude with Endurance. i.e., "If we get stuck, what a wonderful place to be stuck in." They were totally comfortable with the possibility of going in and not coming out -- a risk worth taking in exchange for the amount of science to be gained.

[Floyd]

I'm not sure that any good would come of trying to get to the bottom of the "talus pile" between the rim and the central dunefield since that will be a jumble of rim rocks, windblown dust and weathered fragments with little or no in-place bedrock exposed (or so I see now). The central dunefield would be suicidal: these are active, shifting dunes which have been found to be soft and dangerous to drive upon.

If Opportunity stays on bedrock, which seems wise, then bays A1 and P2 are clearly the most attractive as they extend ~80 and 60 m on bedrock toward the center of VC. Bays K1 and L1 hit dust (talus pile) almost immediately. The amount of exposed bedrock on a bay seems as important a factor as slope in picking an entry point.

[climber]

Very nice, but I don't want to hear from Dr. Cassée Roue who works on the Spirit team.

[djellison]

I recall that was the attitude with Endurance.

Then why all the tests to see if the rover could climb back out again

Yes - it was 'if we get stuck what a nice place to be' - but that's not the same as 'we're going in and don't care if we can get out' They tested to see if they could get out, they were fairly confident that they could, and went in knowing that they would almost certainly get out again.

Doug

[mhoward]

I recall that was the attitude with Endurance. i.e., "If we get stuck, what a wonderful place to be stuck in." They were totally comfortable with the possibility of going in and not coming out -- a risk worth taking in exchange for the amount of science to be gained.

But they would not risk certain things within Endurance, like getting too close to the central drifts, or, I don't know, RATing Burns Cliff maybe - because there were still things to do after leaving. Here... Once they've exhausted the 'safe' things to do (and that will be a long time from now I'm sure), they might take a few more risks to get to the really tasty outcrops, before implementing any 'exit' strategy.

[RNeuhaus]

The decision to go down from the mountain or hill is one of the most complicated that I have. I had to study a lot it, searching the best way to get out (climbing) after studying the surface kind, slope and distance and also evaluate the capability of the truck to run out. This is the same thing that the rovers will apply before deciding to go down.

But, I agree as many others says that if the drivers knows that Oppy wouldn't be able to get out from the crater, the decision to go in only when the wealth of science from VC's insde is wealth worth enough.

However, I feel that in VC there are many ramps and exit ways. However, sure that going down there are more possibilities and it is much easier than to climb back which there are fewer possibilities of exit.

In many cases, the speed is very helpful to overcome the steep slope. However, Oppy is very very slow and but it is very versatil and light and the best way for Oppy to get out is on firm land slope as ones of Endurance Crater.

Rodolfo

[JRehling]

I wouldn't be suprised to see a full circumnavigation - think of the reasons why you would want to..

1) Image all sides of the crater from 3 pan positions

Implicit in this: To get good resolution of all exposed layers -- it's better to see a spot from a 200 meter chord away than from all the way across the crater. In fact, more than 3 positions would be ideal, but not all of them would have to be a full pan. Also, TES is as important as Pancam, assuming it is still working through all of this. A lot of what is seen won't be touched -- TES is the best form of analysis for that stuff.

[Stephen]

If Opportunity stays on bedrock, which seems wise, then bays A1 and P2 are clearly the most attractive as they extend ~80 and 60 m on bedrock toward the center of VC. Bays K1 and L1 hit dust (talus pile) almost immediately. The amount of exposed bedrock on a bay seems as important a factor as slope in picking an entry point.

On that score, the dark slopes below the bluffs in those orbital pics that Tesheiner & others have been using for their route maps (eg this one) are suggestive (to me) more of scree slopes than rock ones. Especially given the streaks radiating in in many places, going from the bluffs all the way down to the dunes.

Still, we can but hope.

======
Stephen

[jamescanvin]

A drive tosol (946) - One of the little test ones I suppose - I guess that means the checkouts yestersol were fine.

CODE

946 p0665.03 10  0   0   10  0   20   navcam_5x1_az_108_3_bpp
946 p1151.04 2   0   0   2   0   4    front_hazcam_idd_unstow_doc
946 p1154.01 2   0   0   2   0   4    front_hazcam_idd_unstow_doc
946 p1201.05 2   0   0   2   0   4    front_haz_penultimate_1_bpp_crit17
946 p1213.00 2   0   0   2   0   4    front_haz_ultimate_3bpp
946 p1275.01 2   0   0   2   0   4    front_hazcam_0.5bpp_pri_41
946 p1301.04 2   0   0   2   0   4    rear_haz_penultimate_1bpp_pri17
946 p1313.02 2   0   0   2   0   4    rear_haz_ultimate_3bpp_pri15
946 p1375.01 2   0   0   2   0   4    rear_hazcam_0.5bpp_pri_41
946 p1585.00 4   0   4   0   0   8    navcam_cloud_4x1_dwnsmp_RVRAz_calstart
946 p1585.00 4   0   4   0   0   8    navcam_cloud_4x1_dwnsmp_RVRAz_calstart
946 p1965.03 10  0   0   10  0   20   navcam_5x1_az_288_1_bpp
946 Total    44  0   8   36  0   88

[Astro0]

While the view ahead is incredible, a good photographer or explorer knows to turn around and look at what's behind you.

I noticed in these thumbnail Hazcams from the short drive away from Emma Dean Crater that there appears to be some nice clouds above Meridiani. I've compiled the shots into a 517k .gif animation. The ground was brightened a bit to show more detail. I'm assuming these are clouds and not lens flare.

File:517k

Enjoy
Astro0

[Nix]

cool

Nico

[ngunn]

A quick question for the geomorphologists - sorry if this has appeared in a different thread before. Some of Victoria's cliffs appear more or less vertical. The usual way to form vertical cliffs on Earth is by erosion from the bottom. Is erosion from the bottom a plausible mechanism inside Victoria, and if not how else do you form vertical cliffs?

[MahFL]

Well spotted, I normally ignore those thumbnails.

[Reckless]

Nice animated gif Astro0. I like the clouds very cirrus, I suspect they are very high up, also the the light on the soil is just about right.
Thanks
Roy F

[Bill Harris]

Some of Victoria's cliffs appear more or less vertical. The usual way to form vertical cliffs on Earth is by erosion from the bottom. Is erosion from the bottom a plausible mechanism inside Victoria, and if not how else do you form vertical cliffs?

Bluffs and ridges are formed when a less-resistant (to erosion) rock is overlain by a resistant unit. By Earthly example, in the eastern US with a wet climate resistant sandstone overlies easily dissolved (or weathered) limestone and forms sandstone ridges and limestone valleys. In the dry western US, limestone is resistant to erosion and forms hills and ridges.

What we are seeing here is that the unit underlying the cliff-forming evaporite is less resistant to aeolian erosion and tends to be removed. No idea what the physical properties of the weak unit are, but that remains to be discovered. The cliffs are vertical because as the support from the underlying unit is removed the upper resistant unit fails along vertical joints or fractures. One early example of an incipient slope failure is Fred's "Sluffing Slab".

--Bill