[X] My Assistant

[Stu]

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

[MarkL]

Beyond doubt she is Steep and Deep as speculated back here

http://www.unmannedspaceflight.com/index.p...ost&p=66333

This could easily take 500++ Sols to circumnavigate with numerous fascinating spots to stop and view. Finding a safe entry ramp will be a challenge. Caution is in order for this highlight of the mission.

Once we see the whole view, I think we'll have the impression it is a saucer rather than a pit because of the enormous scale of the thing (even though it's got to be over 70m deep IMHO). No doubt the sides are pretty steep, but the bottom must be quite flat to accomodate the large dune field. I was earlier under the impression that the southern rim was elevated above the plains but does not appear to be so from the current vantage point.

Thanks so much to the image processors for grinding away at these excellent and exciting views. It's nice not to have to wait until the busy folks at JPL get around to prettifying them.

[fredk]

Impossible to comment on everything I want to - thanks a million guys for the parade of panoramas!

We can now see what part of the far rim we saw in the first glimpse from sol 929-39. Here I've lined up a sol 939 pancam (top) with a 943 view:

What we were seeing was basically just the left rim of Sofi. (Btw, where did the name "Sofi" come from?)

This demonstrates the astounding mapping skills of Tesheiner: in this post his sight line for his feature B almost exactly points to the left rim of Sofi!

What we didn't know in trying to ID the features then was that we weren't seeing the jagged part of the rim at all, just the smooth upper regions and Sofi.

[mhoward]

Michael, that Navcam 360 is awesome too, do you have an anaglyph of that one?

Nico

Thanks. I don't. I might try one tomorrow, or at least put the R camera pan together and let someone else combine them into an anaglyph. Unless someone else does it first.

[RNeuhaus]

A good question?

I have the impresion that from the Sol 943 Oppy ride, the slope starts to go down a little. The reason is that now, I can see more the upper rims. Is that true, isn't?

Rodolfo

[MarkL]

A good question?

I have the impresion that from the Sol 943 Oppy ride, the slope starts to go down a little. The reason is that now, I can see more the upper rims. Is that true, isn't?

Rodolfo

Check this post by Tesheiner. It is an issue of geometry. The camera is a long way from the far rim and quite close to the near rim (you can think of it as a long lever between opportunity's camera and the far rim with the fulcrum on the near rim). As the rover approaches the near rim the far end of the lever moves down quite quickly so the camera sees a lot lower down. The local slope has very little to do with it.

[fredk]

I've redone my slope calculation for the large bay almost directly across Victoria from us, using the pancam imagery. When I did it with navcam yesterday, I estimated 16.5 degrees for the slope of the upper bay.

With pancam, there's enough resolution to break the measurement into two parts: the uppermost bay, between the black and grey dots in these images, and the mid bay, between the grey and white dots:

The result: Uppermost bay slope 14 degrees, mid bay slope 18 degrees. I estimate uncertainties of plus or minus 1 or 2 degrees on these figures. This is about as far as we can push this technique since it's now limited by the resolution of the orbital image, though it still would be interesting to measure the slopes of other bays for comparison. At any rate, we're safely within traversable limits here, at least with a good surface.

As Climber pointed out, a foreshortened slope can look much steeper than it is. The cliffs are definitely much steeper than the bays, but it's hard to ID features to get an actual measurement.

Edit: the bay I measured was H1-I1 (and more precisely the H2-I1 side of it) I1 according to James's new naming scheme. Also the pancam crop is 2x vertical stretched.

[ElkGroveDan]

I've redone my slope calculation for the large bay almost directly across Victoria from us

Hey Fred when you have a minute could you track down mystery man? Both in pancam and navcam shots since we have the foreshortening issue, on which I agree with you and climber. Last time I saw him he was over in Gusev .

[Guest_paulanderson_*]

Some pronounced horizontal layering on the far rim visible now, stretching across the field of view in some of the new pancams:

http://qt.exploratorium.edu/mars/opportuni...00P2382R2M1.JPG

[alan]

I've been wondering about that myself. What is the layer just above the red line?

Could it have been the top layer when Victoria formed with the material above added later?

[glennwsmith]

A stupid question, but -- what is the layer of white stuff along the crater rim?

[climber]

(Btw, where did the name "Sofi" come from?)

Shaka was the one that gave this name to pay credit to Sofi Collis who named Spirit & Opportunity. Its has been used then "internaly".

[jamescanvin]

A stupid question, but -- what is the layer of white stuff along the crater rim?

Well not white, bright in L2 (red).

Nearly all bright things in L2 have been exposed evaporite - and there will be plenty of that along the rim!

[CosmicRocker]

I don't have a lot of compassion for the Team's "overwhelmed" feeling. They brought this on themselves by doing such an "overwhelmingly good job" with this mission from the get-go. I mean, do we realize how difficult it is to do this kind of thing repeatedly, as these people have done? The MER teams have become the dream teams that have put NASA and unmanned space exploration back to front and center on the stage. I have got to imagine that all the concern about NASA science going down the tubes is pretty much mitigated by the wild succeses of these intrepid pioneers.

I too am overwhelmed, as I try to catch up with the imagery and the many postings by members here since the terribly clipped, but amazing pancams came down. It pretty much took me all night to ingest all of the information contributors have provided. In our enthusiasm, we are always eager to start interpreting details that are not yet clearly visible, and that is a large part of the fun we have here as the discoveries trickle in. Keep them coming, but remember that things may appear somewhat differently in a few sols.

I am encouraged by fredk's slope calculations. As for the sloughing slab, it looks very much like a warped bedding plane that could be the result of the impact disruption, or post-impact deposition over a pre-existing surface. I wouldn't dismiss Shaka's suggestion just yet, as his comments seem to be aligned with the regional observations in the Edgett paper. We need to get up cose and personal with this road cut before we can start to confidently interpret what we are really seeing.

[climber]

Some pronounced horizontal layering on the far rim visible now, stretching across the field of view in some of the new pancams:
http://qt.exploratorium.edu/mars/opportuni...00P2382R2M1.JPG

I posted a question on this subject that was tentatively answer by Shaka & All.
Now, I just notice on Fredk "slope" mesurement that the horinzontal layering is ALSO visible on MGS pictures of VC : see Fredk's post 8 posts above

[jamescanvin]

But you know, there are plenty more bays on this "shore", and there's nothing like independent confirmation to boost the confidence of even a "great mind".

Well I did do a quick check using the navcams yesterday and I did get the same answer.

With regard to other bays, a couple of rough calculatons give:

18 degrees for Bay K1 (just to the right of Sofi)
25 degrees for Bay J1
25 degrees for Bay F1 - although we're not looking squarely onto the slope so this is probably an underestimate.

James