[X] My Assistant

[Stu]

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

[djellison]

Look at the MOC DEM movie - the duck bay slope looks NASTY - I would estimate as much as twice as steep as some of the slopes on the South and South Eastern edge of the crater.

Doug

[Stu]

No colour views yet, so here's another bit of fun...

[Nix]

Wouldn't the steepest slopes be where the distance to the dunefield is minimal? As seen in the orbital images the dunefield is not smack in the middle.

Nico

[Tesheiner]

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

It will depend on what they are made of.
If they are mostly sandy or with some slippage I don't see how we would be able to leave the crater.

[MahFL]

And who says we are leaving the crater after we go in ?

[fredk]

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.

This is great, James! It's basically the sort of picture I was expecting. If you look at the bays you and I have measured on the orbital image, the "longer" bays (ie those that extend farther away from the centre of VC) are less steep.

As others have just written, for this reason I'd expect Duck Bay to be one of the least steep. (Actually, I think B1 might be even a bit less steep.)

However, recall that the near rim is considerably higher than the far, and also recall the jpl 3D model animation which strongly suggests that the slope inside the near rim is quite a bit steeper than the slope inside the far rim. We can't be sure yet that Duck Bay or B1 will be traversable. Edit: I see Doug just scooped me on this point!

As far as circumnavigation goes, I agree with Doug that it would be easy given the mobility here. However, I suspect that the lure of deep strata will be too tempting and that if (I think it's likely) Duck or B1 are deemed enterable then they will go in fairly quickly. Recall that Endurance could have been easily circumnavigated but never was.

However, as it's still winter, entering at Duck or B1 is not ideal in terms of having the rover tilted towards the sun. But as spring approaches it may not matter much anyway.

[MahFL]

Remember, the main purpose of going to Victoria is to examine the rock layers at the BOTTEM of the crater, you know, actually driving down there and sticking the arm on the layers.

[centsworth_II]

It remains to be seen how deep the lowest intact layers are -- and how easy it would be to get to them. Remember, they gave up trying to get to the upper reaches of the mega ripples in Endurance and they were just a few feet away. Opportunity never got more than halfway to the bottom of Endurance.

Even if The inside of Victoria is Opportunity's last stop, I would say it would take at least a year to explore the "safe" areas before what can be learned there is tapped out and the decision needs to be made: leave the crater or attempt exploration of desireable targets in more risky parts of Victoria.

[climber]

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

Sorry, did I misunderstood what you wrote to me ?

Climber, I'm reluctant to rise up a discovery I made just now : There's apparrent "caves" in the horizontal layer on the far rim on the left of Sofi. Can you spot them? I'll be killed this time if I'm wrong so I though you could do it for me. OK, now, can you write a post telling it's YOUR discovery? Obregado
Ustrax

OK, it's a forgery but it COULD have been true

[RNeuhaus]

You can see in detail about the attack plan in Victoria Crater at the space.com

Des Marais said that there are important discussions to take place over the next few months: Is there enough science value by driving into Victoria Crater? If so, is that research of first-rate importance if rover handlers can’t wheel Opportunity back out?

If it is so, it would be terrific!

Rodolfo

[Bill Harris]

Doug Ellison:

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

I agree with all those reasons, and more. The only way we will get a good analysis of the stratigraphy and lithology is to look at the exposed outcrops in the Capes from from both sides, full filter set images, varied lighting and with the miniTES. Remember, we are looking for lateral changes in the evaporite over the crater diameter as well as point-to-point differences. Although Oppy could try to enter the crater in a Bay to get a close look at the layers, this might be risky so it would be best done after the circum-traverse. It would be good data, but only collected as a "phase 2" effort. 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.

We are best served by keeping the operational Oppy mobile while we can, once we have a wheel (etc) failure then it can be made into a sessile base station.

--Bill

[climber]

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

Here is Des Marais interpretation : "However, preliminary evidence from orbit indicates that southeast of the crater represents perhaps the most approachable trajectory to get inside the crater—if that go-ahead is given."
Not far from what you think, eh ?
BTW, Do you know what Des Marais means in French? "From marshes". Prophetic ?

[ElkGroveDan]

BTW, Do you know what Des Marais means in French? "From marshes". Prophetic ?

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

[djellison]

And who says we are leaving the crater after we go in ?

If we have a healthy vehicle once all available outcrop has been examined.....who says we're not?

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 - but I hope some consideration is given to extraction when deciding an entrance strategy.

Doug

[Guest_Myran_*]

MahFL wrote: Remember, the main purpose of going to Victoria is to examine the rock layers at the BOTTEM of the crater.....

I am sorry to say, but there are no accessible bedrock at the bottom of Victoria crater, only sand. The rockface we can study are along the rim, but like most I do hope the rover will crawl in and have a look at the lowest strata that it can reach. Hopefully we'll get a lookback into one age older than those Endurance crater gave us some hints about.