Victoria's Innards, Your last chance to speculate before we really see it Options

[dvandorn]

So, here's a nice little short-term thread, to let people get on the record with their wild speculations as to what we'll see when we get "up close and personal" with Vickie.

Some have mentioned seeing gully-like features in the walls, in the MOC images. I'll take this moment to disagree -- it looks to me like the talus slope (which makes up most of the exposed interior of the crater, that and the dune field) is streaked all along the interior, and that some streaks swirl a bit as they approach the upper rim. I think what we're seeing here is mass-wasting down the slopes of a non-homogenous surface. While the bulk composition of the surface layer that's slowly falling into Vickie is probably all pretty similar, there are obviously pockets of lighter and darker materials. Those pockets are sliding down into the crater, leaving a striated look as light deposits slide down adjacent to darker ones.

At this point, the wind circulation system within the crater kicks in, modifying the light and dark streaks -- especially near the upper rim around the capes and down into the bays.

I think the gully-like feature leading down from Duck Bay is probably nothing more than a mass-wastage slide of dark material down into the crater that has been swirled up a bit near where the winds howl in through Duck Bay.

Let's see, what other potentially embarrasing predictions can I make? I think that while the dark spots on the far rim's cape structures aren't entrances into deep caves, I'd bet that some of them are shallow "alcove" caves. Places where softer rock have been windblown out of the near-vertical rock face, leaving dimple-caves in the rock.

While these would be great places to repel down into and set up a sleeping bag for the night (the cliffs keep the big predators away, after all... ), I doubt a MER would ever be able to make its way into one...

-the other Doug

[diane]

One of the tricks will be figuring out Vicky's age. If, as many suspect, there was a lot of groundwater (ground ice) still in the soil when Vicky formed, there would possibly have been gullies formed down the sides of the original Victoria crater, just as we've seen gullies in other Martian features in many places. However, the mass wastage process has probably destroyed them all, and in fact has probably also covered any other original evidence of age, with the possible exception of the upper portions of the cliffs that haven't yet collapsed.

I think we can forget about RATting any cliffs. If we can identify any debris as being specific to a particular layer or even a particular spot on a particular cliff, that's probably as good as it gets. But the cliffs will be unapproachable, just as Burns cliff was in Endurance.

There will be dimple caves; that seems to be part of the mass wastage process, since the lower layers seem more susceptible to wind erosion than the upper layers. Sitting under an overhang would definitely be high-risk, although probably not in the time-frame of Oppy's visit.

Vicky is not an exhumed crater. I went looking for photos of other exhumed craters on Mars; there's just no ressemblance.

I'm concerned that Vicky's interior may be mostly unnavigable, due to tallus. Check out this photo of tallus from Mt. Wilson: http://shallowsky.com/images/geology/wilson-landslide.jpg Not that this is entirely bad; we haven't really seen erosion on this scale anywhere along Oppy's or Sprit's paths.

[climber]

I think we can forget about RATting any cliffs.

Diane,
Not at all, not all all! I've got another exemple. You know I'm not a geologist but I've got some experience hiking the mountains and I want to share this one. My wildess dream will be to actualy Rat the cliffs and I believe it IS possible because I hope we can get to the "horizontal feature".
Let me show you what I mean. This horizontal feature is still very far and I guess it could look a little bit like this (I'm talking of the upper part since we know that the lower is different from this) :


Pretty steep eh? Now, look how it looks like when you're actualy there :


Convinced ?
I'll dedicate my time looking pictures to find out a place where Oppy will have a chance to get there.
That's the big difference as compared to Endurance. The feature could be a kind of terrace. They call this "Faja" in Spain. These pictures come (once again) from el "Parque National de Ordessa y del Monte Perdido" and it's called "Faja de las Flores".
What about 2007 UMSF meeting there?

[diane]

Diane,
Not at all, not all all! I've got another exemple. You know I'm not a geologist but I've got some experience hiking the mountains and I want to share this one. My wildess dream will be to actualy Rat the cliffs and I believe it IS possible because I hope we can get to the "horizontal feature".
Let me show you what I mean.
<photos snipped>
Convinced ?

Not convinced, but always open-minded. There's no way to know until we're there. I do worry about Oppy's footing. (Perhaps not quite the right word.... Maybe what Oppy needs is monster truck tires.)

Anyway, I'll look forward to your expeditionary reports! This forum is so addictive because of the wealth of knowledge and viewpoints that everyone brings.