[X] My Assistant

[Stu]

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

[Nix]

The layer IS visible in the orbital images. I traced it when noticing this 'overhang' on the southwestern part of the rim.

The overhang looks thicker than the depth of the evaporite layer at the far rim, but the far rim being lower...

Nico

Attached thumbnail(s)

 

[climber]

The layer IS visible in the orbital images. I traced it when noticing this 'overhang' on the southwestern part of the rim.
The overhang looks thicker than the depth of the evaporite layer at the far rim, but the far rim being lower...
Nico

Well, now we know that it's (will be) mesurable verticaly (from the ground) and horizontaly (from MGS').

Now, there's no reason the layer is limited to far rim so, once at Duck Bay, we'll probably see it under Cape Verde & Capo Frio very close to us. As near rim is way above far rim, it'll be very interesting to see if this layer is at the same relative depth on near rim (taking the rim as a reference) OR if it's at far rim depth (taking the plain as a reference) i.e. some 6 meters further down. Very interesting stuff there (not taking in account that I've seen caves in the layer )

[Bill Harris]

RE: Post#174, alan: "What is the layer just above the red line?"

My initial idea? The horizontal layer immediately above the red line represents the Meridiani Plain surface at the time of the Victoria impact and the somewhat hummocky material above is the ejecta blanket. The orbital images suggested a number of flat slope failure or slump areas along the rim, but these first Pancam views re-suggest this persistent unit.

With the classical model of a crater rim there are upturned and overturned beds at the crater rim but may be that the evaporite is too weak to form upturned beds and traceable overturned beds. And, of course, the present rim has eroded back several meters from the original rim.

--Bill

[ustrax]

Climber!!! Now I'm gonna be silly dreaming of martian caverns until we get proper lighting on those shadows. Did ustrax put you up to this?

I told him NOT to talk about this to anyone but did he listen?...

[algorimancer]

I've redone my slope calculation for the large bay almost directly across Victoria from us, using the pancam imagery.
...
The result: Uppermost bay slope 14 degrees, mid bay slope 18 degrees....
At any rate, we're safely within traversable limits here, at least with a good surface.

By extension, if we assume that the evaporite layer is relatively uniform all around Victoria, then it looks like Duck Bay is indeed (and reassuringly) the lowest-slope entry into the crater, based upon the horizontal extent of exposed evaporite in the overhead view. Really convenient that Duck Bay just happens to be on the nearer side of the crater

[Gray]

Bill,
I agree with yoru interpretation that the white line along the rim represents the evaporite bed that is the Meridiani plain surface covered by the overlying ejecta blanket and aeolian deposits.
The jagged shape of the far cliffs look to me like joint weathering.

[ngunn]

When we get to the rim in a few sols, the views of the nearby 'cape' exposures will (probably) be so dramatic as to completely overshadow this amazing view of the far side (he predicted).

Phil

From a strictly geological point of view you're probably right, but I'd like to make another prediction. However spectacular the views get from now on, the one we have now will always stick in people's minds. It has a special epic quality: it portends great revelations, something which can never quite be repeated. Also the far side cliffs are all the more dramatic for being only partly visible - they may well seem smaller when we see the whole interior spread out below them.

[odave]

... looks like Duck Bay is indeed (and reassuringly) the lowest-slope entry into the crater...Really convenient that Duck Bay just happens to be on the nearer side of the crater

Do you think they'd want to circumnavigate the rim before trying to enter?

[MahFL]

Not a chance, the circumference would be about 2.4 Km long.

[odave]

Yeah, I'm guessing we may see something like the sequence at Endurance. Drive far enough around in one direction to get good images of all the faces, ID a good entry "bay", then drive for that & take the plunge.

[djellison]

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
2) Generate an excellent DEM for planning
3) Use identified slopes for positive power
4) Mobility is VERY easy around the rim, 50-100m/sol it would be perhaps a 3 month trip to lap the crater and have 3 pan stops en route. ( 2500 / 70 = 35 driving sols. Double for restriction + 3 x 5 sols of imaging = 85 sols )

THEN - you can decide where best to go into the crater when we're getting toward mid Spring.

Considering that it's FAR from certain we'd get out of this thing, it would make sense to document the hell out of it before we go it would it not?

I would be certain of 120 degrees of circumnav - I'm expecting as much as 180 degrees because the southern side may well present the best entry options when looking at the MOC dem - and I would not be suprised at 240 degrees +

Doug

[climber]

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

I agree, the only restriction would be if Duck' bay is the ONLY place we can enter VC, but, as Mark Adler says on TPS blog : "we always find a way"

[akuo]

I think Duck bay looks like the best place to enter from the satellite images. I think they'll go straight in after the initial pancam mosaic from either near cape. But we'll see what we see :-)

[MahFL]

If the slopes are only 16 to 20 degrees, driving in and out will be easy. Endurance was a lot steeper than 20 degrees.

[ustrax]

If the slopes are only 16 to 20 degrees, driving in and out will be easy. Endurance was a lot steeper than 20 degrees.

Maybe I'm being a bit pessimistic but, from what we've saw so far from the far rim, I can only a few possible places (yeah...We only need one...) where Oppy can make an entrance and they're all in sites not imaged yet...There are two who I consider the best ones, they are presented in green, the others in orange...Humm...I just don't know...Looks everything so steep...

http://i16.photobucket.com/albums/b14/ustrax3/posent.jpg