Nico, I would hazard a guess (then duck) that this used to be overburden on top of the crater rim which was undercut by erosion or weakness in the stuff under it so it slumped down and now rests on a 45 degree incline. It looks like strata, not a fracture.
<Gray -- you nailed it>

Hey Nico or any of the Imaging Tech Guru's in this Forum

From this image:

http://qt.exploratorium.edu/mars/opportuni...EKP0673L0M1.JPG

Can anyone take a side shot of one of the rovers and insert it onto the bluff sticking out into the crater?
I want to see how small the rover would be compared to the bluff and crater?

Thanks

In this case, we are seeing Victoria by photograph; there's no way that any of us are likely to see this in person. Photographic "effects" are entirely appropriate, and we're so used to seeing other photographic effects in rover images that we've learned to filter them out. For instance, the pancam is the only camera that gives a relatively "true" proportion; the navcams are very wide-angle lenses, and the hazcams are fisheyes, both of which have characteristic distortions.

I'm sure that Stu placed the sun lower in the sky than Oppy would normally photograph, again for dramatic effect. (What time-of-sol does Oppy normally shoot her photos, by the way?) Shooting into the sun like that, there's no way to avoid lens flare.

Stu, that's really, really nice work. I know the sand isn't that white, but it reminds me of the white sand beaches of west Florida. I've had that same impression from the unmodified b/w images of Victoria, too; the sand at the top of the cliffs and along Duck Bay looks almost like snow. You really captured that!

Yestersol the navcams were started at 13:34 LST and the pancams at 13:37 so yes the sun would have been much higher in the sky. But that's not the point I love the shots with the sun added, lens flare and all, good work Stu.

Tosols pancam plan:



4 pointing (2x2?) colour mosaic of each cape - yummy!

James

Man, oh man!!!!

All I can say is...

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-the other Doug

According to the Pancam database activities of Oppy at the sol 952, the plan would be: 1) advance to a middle point between Cabos and then take two colorfull pictures on them.

Rodolfo

Well, I had to give this a stab myself. I picked a low point between dunes, see white spot in this image, 347 metres horizontally from the sol 951 location:
Click to view attachment
and identified it on tosol's pancam imagery:
Click to view attachment
(The projections from I think it was Indian3000 helped immensely!) Instead of using the rover orientation info, I made one simple assumption - that the visible horizon to the east lies at 0 degrees elevation. Then I just measured the angular elevation of the point in question: -11.4 degrees. Trivial trig then gives the depth of the point as 70.1 metres relative to the rover.

Pixel measurement errors here are negligible. The only real uncertainty is the elevation of the horizon. Eg, if it were -1 degree (ie the ground sloping downwards to the east), the depth changes to 76.4 metres.

Anyway, this agrees well with your estimate and what we've been hearing through official channels.

Nice work, algorimancer and fredk. It is encouraging in a number of ways that your results agree so well, even though an important assumption differed between your methods. I'd say we can have quite a bit of confidence that the depth is pretty close to 70 meters.

Thanks David, good question. The answer is that I do a lot of public lectures, and sometimes shamelessly and blatantly look for a "wow!" audience reaction, and this image was deliberately created with that in mind. I'm giving a big lecture at a theatre here in the Lake District Friday night, and while I'll be showing a lot or raw and stitched images, any speaker will tell you it's always good to have a couple of "showstoppers" which are used for a WHAM! visual impact moment, but, of course, always used with a thorough explanation of their artificiality, to 1) not lie to the audience, and 2) help that audience appreciate the real pictures more.

Fully agree! Sky is beautiful!
You should try to make same hue/sat on the full crater...

[quote name='Nix' date='Sep 27 2006, 03:02 PM' post='70140']
This look right?

If the horizontal blockiness is the pre-impact stratigraphy, and the 45 degree angle layers are shock effect or angle of repose mass wasting, is the finer grained lighter colored stuff on top of the bluff the total thickness of the ejecta blanket of victoria?

Or have I been bashing my head with bricks too long?

Brian

That's lovely...but I'm a little unimpressed with the dunes that looked so awesome in the orbital imagery, now that I can see them from the ground. Sure, they have an amazing form and structure, but I'm getting them to be about 30px high at 250m range. Say 2-2.5 metres in height, even given that we're looking down on them?

"Aren't you a little short for a MER-eating monster?"

Andy

Edging a little closer...

http://qt.exploratorium.edu/mars/opportuni...EVP1212L0M1.JPG

I am not sure of the best place to post this, but I am attaching below a link to today's Washington Post article on Opportunity's "edging closer" to the rim of Victoria. The headline is:

"Mars Crater Is a 'Dream Come True'
Scientists Marvel Over Never-Before-Seen Pictures of Victoria as Rover Moves Closer"


http://www.washingtonpost.com/wp-dyn/conte...?referrer=email


One interesting tidbit from the article:

"NASA scientists said the rover came within about 15 feet of Victoria Crater's rim and was scheduled to climb over a small sand dune last night and stop right at the crater's edge.

"The pictures we got tell us there is a tremendous amount of geologic information hidden in that crater," said Steven Squyres of Cornell University"

I'll agree some of the other posters here that the steep lines you've outlined are not originally layering. There is some original, horizontal, layering visible through the intense fracturing, especially on the near-vertical cliff facing into the crater in this view.

In addition to other other possible explanations already given for the steep surfaces you've highlighted, I'd add pressure-release (onion-skin) sheeting from excavation of the crater material. The key indication for this is that the fractures are subparallel to the crater walls.

Only two hazcam images from tosol so far, but even those show new terrain. The slope to the left of Oppy near the wall of the cape looks benign for driving.

Back in the day when I played flight simulator games and 3D graphics accelerator cards were just coming out, everyone and their brothers were adding lens flare to cockpit and external views when you were looking near the sun. The purists were always complaining that if you were really there, you wouldn't see a lens flare. But the guys who were just in it for fun would say "yeah, but it feels more real".

After a while, lens flare became a bit of a cliche. In my day job, I'm a software developer working on an industrial robotics 3D simulation product. I'm always telling our 3D guy that we need to add lens flare when you look at an arc welding 'bot in action. He just rolls his eyes.

But I agree, it does add a "coolness" factor when you see it

What a tease....navcams navcams, my world for a navcam...

By the way, can someone tell me what the distance is between the star like patterns the wheel tracks make, thanks ?

Significantly closer! We may now be able to see the surface of Duck bay from the cameras on the mast.

Click to view attachmentClick to view attachment

You can see the shadow of the mast pointing at the left hand cape.

Pi D = circum.

So PI x 25cm = 78ish cm

(Wheels are 250mm face diam, 262 to the cleat)

So - two cleat marks can be anything from 78 - 80cm basically.

On tracking data - I make the drive approx 4m, which would tie in with the number of visible cleat marks in this http://qt.exploratorium.edu/mars/opportuni...EVP1312R0M1.JPG

Doug

Thanks Doug, I have often wondered about that, I could have course looked up the wheel diameter myself and done the mathematics, but I knew someone here would know it. I think a drive down to Cape Verde on the left is in order next week.

New pancams and Navcams are up !

http://qt.exploratorium.edu/mars/opportuni...cam/2006-09-28/

OM.... ! at the new Navcams..

1P212696162EFF76EKP2388L7M1



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http://nasa.exploratorium.edu/mars/opportu...EKP2388L7M1.JPG

In case of anyone having doubts...We won't leave this place so soon...

Yup,

http://qt.exploratorium.edu/mars/opportuni...EKP2388L7M1.JPG

is amazinggggg,

but

http://qt.exploratorium.edu/mars/opportuni...EKP2389L7M1.JPG

makes me equally happy, because it shows that Oppy will definitely be able to enter the crater.

I wouldn't put that as a certain entry point....it looks like it might be 30ish degrees. BUT...given that the MOC work shows the far side to be less steep than this side....I would be very hopefull of an ingress AND egress point on the SE side.

Doug

The surface down to Cape Verdi looks like the test surface they constructed when they were testing before entering Endurance.

How tall is that feature? I can't get a sense of scale!

The navcams show what seems to be a very clean ingress route...

Oh - it's good - and probably navigable - but the MOC imagery would suggest the SE side is therefore even more navigable.

Doug

Its less than 30 degrees Doug.

This one ?

Thats an ongoing problem with Mars as there is nothing to compare the scale to from Earth.

I remember once wondering whether the pancam mast could be lowered to horizontal again, in case a lower center-of-gravity would be needed for navigating a slope. Would it be possible in an extreme case, or was the mast-raising a one-off operation?

It is true that the slope we see in the picture might not quite be navigable, also taking into account that the image is slightly inclined. -But there IS a wonderful rock wall with a nice parking spot in front of it at the bottom of the slope. However, if the sunlight doesn't cooperate, then it is of course a no-go...

Back to drooling...

That is a new (geological) world that just opened at Meridiani, isn't it!

But you know Rovers dosen't like sand. It seems to be a bit more sandy as in Endurance in order to reach the interesting points...

I think it was a one off - there were latches involved etc. Even if it could be - the mass of the mast compared to the mass of the vehicle - I can't imagine there being a great deal of benefit.

And - as with all such things (i.e. fold up the arrays to clean them etc ) imagine if it didn't deploy back up again...what sort of mission would you have then.

Doug

Yes, that one...

That's as good an invitation as I've ever seen. A nice little nip down that slope, some RAT'ing on the rock wall and then back up the ramp for a new ingress point along the circumference of Victoria. Heady times...

Yes, regarding the mast, I imagine there were latches "clicking into place" and whatnot when they raised it. Even if they could it would have been a last-ditch operation obviously.

Uh oh.....

Click to view attachment

I'd say about 80 to 100 feet high.

http://www.unmannedspaceflight.com/index.p...ost&id=7742

This has got to be one of the most scenic images produced to date by Oppy. We're definitely not in Kansas (annulus) anymore! Now where is the 3D?

Amazing views.

With these, there is also some sadness. I can't imagine Opportunity ever leaving Victoria. So this is also her resting place.

Still, there is so much to discover. The capes and bays almost makes Victoria like a series of craters, there is always something new behind the wall of the nearest cape!

Click to view attachment

Interesting. Way back when we were discussing this before we got onto the approach I had used the shadows on the MOC imagery to estimate that these cliffs shouldn't be more than 12m tall. Can anyone provide a definitive answer are we dealing with 8-12m or 27-33m?.

Looking at that entry ramp has got to have the scientists at JPL wetting their pants. Wasn't it thought that the ramps along the north side of Victoria were more likely to be scoured free of dust aside from the small dunes created at the very edge? Even if the ramps on the far side are a bit less steep, if they have less grippable surface, then here would be preferable.

Hey and you know what the Sand People do with 'driods, right?

Words fails me so I'll just post a link...

http://nasa.exploratorium.edu/mars/opportu...EKP2389R1M1.JPG