[X] My Assistant

[Stu]

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

[imipak]

anything to expect for this weekend or can I go do other things?!

Personally, I'm spending the weekend waiting to see whether I could have been doing something else.

Tosol (948) I think we'll see some of the short test drives Steve Squyres referred to in the update; we won't make significant rimwards drive until early next week. I've been known to be less than 100% accurate in the past though...

[Nix]

I must admit, Pando had me thinking we had gotten to the rim! I was disappointed - I thought, gee, there's almost nothing visible below the rim cliffs...the whole crater is blanketed by sand! I only realized it was a fake when an hour had passed since the posting and no one else had posted any rim panoramas.

Great job, Pando!!

He had me fooled too (with the thumbnail). The actual scene will be more detailed indeed -although below the cliffs I'm not expecting anything much except some boulders and a glorious dunefield. I wouldn't be surprised, given the orbital imagery we have, if sand is the main ingredient deeper in the bowl.

Nico

[fredk]

Now that the view in front of us has been sorted out (see Duck Bay thread) I can safely place some mystery men at various points along the rim. Here's the jpl R2 pan with several guys to set the scale:

As always, this shows that things are closer and smaller than you may have guessed. Also notice how the men on the far rim really give a sense of the immense gap before us.

[Nix]

Ah! the mystery man, been waiting for this...

Thanks fredk, good to get a sense of the scale ahead of us.

Nico

[dilo]

Great montage, Pando... AND, even if more detailed, I think real panorama will be not too different from this. (PS: I love your Avatar, Dr. Strangelove! )
And thanks for the mistery man, fredk!

I didn't resist to work also on official PanCam stitch, here below a processed/stretched (2.5x) version with, in the inset, the horizon with further contrast increase.

The features belonging to the rim of the "35 Km crater" Troy (?) are very interesting.
What hit me of this VC view is the net horizontal cut in the stratigraphy and the fact that this line establish the vertical limit for the rim. In other words, the most internal rim features (the "capes") ends exactly where this dark line contact the surface material... This cannot be by chance and could be related to a change in the mechanical behavior of terrain OR to the VC genesis itself (is the dark line a deposit of ejected material, covered by eolian transported material?).
Any idea?

[David]

As always, this shows that things are closer and smaller than you may have guessed. Also notice how the men on the far rim really give a sense of the immense gap before us.

Closer, yes. But smaller? Unh-uh! That thing is colossal -- and all the more striking for being situated in loneliness in a flat desert plain, instead of being surrounded by other craters large and small (as would be the case on the Moon).

Worst thing is that those "ramps" are looking much steeper and less navigable than I had hoped. Hopefully the harsh incline is to some extent an illusion.

[fredk]

Actually I meant just the foreground stuff looks smaller than I expected. You're absolutely right that the structures on the far rim are huge and very far away.

James Canvin and I have been measuring the slopes of some of the bays on the far rim (see this post for example). We're finding the shallowest bays are only around 16 degrees or so. That would be easily rovable if the surface is reasonably solid. It's the effect of foreshortening that makes them look steep. I believe the cliffs, on the other hand, are very steep.

[jamescanvin]

I would be more inclined to bet that our azimuth pointing is a hair off and what we're seeing is this feature (cyan circle). Notice that it is apparently large enough to have its own dune field. The image off in that direction is lower resolution than on the left, otherwise I think it would stand out nearly as distinctly as Victoria:
[attachment=7606:attachment]

I'm not so sure, that crater is as far away as the twin peaks and they appear to be on (or over the horizon) the dark mark on the pancams seems to extend several pixels below the horizon, suggesting that it's closer. The image in that direction maybe a lower resolution but there are plenty of smaller scale features present, I don't think that it's just low resolution image of a Victoria class crater, just an old bowl in the ground.

Anyway, lets wait for L7 with it's better resolution.

James

[Nix]

Had a play also with the official pancam mosaic...not much new but we gotta do something eh?

Interesting detail on the other side of the crater, as in dilo's enhancements.



(http://www.awalkonmars.com/PIA08776_fig2 anacrop3xveE2.jpg)

Nico

[jamescanvin]

Also notice how the men on the far rim really give a sense of the immense gap before us.

Wow, that's a great image Fred! Really gives some scale to those cliffs, just imagining tiny Oppy up there (perhaps some 'Mystery Rovers' could be in order) makes me worried about her - this as scary place!

James

[Floyd]

Images in at exploratorium--but few intact. Never seen so many partial images.

[Nix]

indeed much of the data is missing -for now

mystery man visits 3D then.



Nico

[stevesliva]

As always, this shows that things are closer and smaller than you may have guessed. Also notice how the men on the far rim really give a sense of the immense gap before us.

Holy Canoli! It's one thing to know that, yeah, it's 3/4km away, but now those cliffs look ginormous.

[MahFL]

Thats good work, but how do you calculate the size of the men at the different places ? Also how accurate do you think it is ?

[fredk]

I start with Oppy's position from Tesheiner's route map. Then I pick some spots in the rover imagery to place the men. All you need is the distance to those spots. If they're close, you can use Algorimancer to get the distances by parallax. Otherwise you have to identify those spots on the orbital images. That can be very hard. Then you measure the distances from the map.

I assume the man is 2 metres tall from ground to top of raised hand. With the distances, it's simple trig to get the angle subtended by the men at Oppy. Knowing the fields of view of the cameras those angles are translated to pixel height for the men.

For this image I'm very confident of all the positions (as we hammered out in the Duck Bay thread). The men's heights are certainly accurate to 10% and probably 5%.

Thanks for the 3D version, Nico! I thought about doing one, but haven't managed yet.