Victoria here we come..., Arrival minus one month and counting... Options

[Stu]

Now we have a (relatively) firm timetable for arrival at Victoria - a month, I think it was - I thought the time was right to open a new thread on what will greet us when we get there. So, I've been playing about (cue groans from the more experienced image processors! ) with the best Victoria image I could find, and have brought out some interesting features and details I'd appreciate people's comments on, preferably not in Klingon, as I'm still just dipping in and out of my geological dictionary...

I've got three "areas of interest" for you, labelled here... Victoria Crater

1. Spills of boulders and slumping along the northern crater rim and detail on the "Boat Ramp"?

2. Pronounced gully-like feature on western slope?

3. Large shelf on south-western edge?

I hope no-one will criticise the very amateurish effort here, or think I'm putting these images forward as anything special. I'm just trying to get some discussion and debate going. I know this is a less than scientific exercise - I leave the science to you guys, I just like to throw a pebble in the discussion pool and watch the pretty ripples spread out...

[Nirgal]

Now we have a (relatively) firm timetable for arrival at Victoria - a month, I think it was - I thought the time

Thanks for the new thread and the orbiter images Stu
(especially image 2 is amazing: I wasn't aware that we actually have such a high resoloution
view of Victoria at all... which MOC image did you extract this from ? )

Yes, this final spurt to Victoria is the moment I have been waiting for over a year now !

As important and scientifically very necessary all the long intermediate stops at outcrops and small carters
are (and of course we also still have a couple of days of important work do be done here at Beagle !)
it has nevertheless been clear (and stated repeatedly by Steve S.) that the one most important goal
and Oppy's real and actual destination is Victoria.

This final approach with the steady stream of new rim images becoming clearer and better every day
and culminating in the "Great Victoria Pan"
will sure be the highlight of the whole mission, I'm sure ....

Gentlemen, prepare to warm up your image processing engines

[Stu]

Thanks Nirgal!

Original Victoria NASA image

[AndyG]

Hi Stu!

Having seen these pictures I've attempted to humanize Victoria and have played the "scale" game by trying to relate it to something on Earth that I know. How big is it, how would it feel to be standing on the rim? All the usual questions!

And the thing that's just hit me? The phrase "boat ramp". I was born in Cumbria, where you now live, and I learned to sail on Talkin Tarn - perhaps you know it, about half an hour east of Carlisle? It's almost exactly the same size as Victoria. Say about half an hour to walk around it. If drained, you could walk across it in 8 to 10 minutes. On one side there's a ridge of trees not far off the height of a crater rim...I now know what it would feel like to roll gingerly up to the edge and peer across and in! Awesome!

Andy

[Stu]

Hey Andy,

I know that area well... gorgeous... nice to have a more familiar sense of scale for Victoria!

A couple more interesting features, identified on v2 of my map...

4. More gullies or dust slips..?

5. Mini crater on inner slope..?

[Guest_Sunspot_*]

Think you should hold off on this thread for a while lol

[Stu]

Hmmm, maybe... but I have faith in Oppy, and besides, we can still look forward to images of it taken by MRO...

[Bill Harris]

A bit OT, but did we ever find an "unannotated" version of this hi-res Victoria image, PIA08447?

--Bill

[algorimancer]

At this point I'm rather intrigued by a feature which is sort of on the way to Victoria, the big dark region that I've labeled Zeta, just north of the crater Epsilon, which you can see here (sharp pictures, slow load, and the typo "hummock" should be "hillock"),

http://www.clarkandersen.com/Jpeg2000/Jpeg2000.htm

It also lies under the '6' in 156 in this image posted by Stu:

http://photojournal.jpl.nasa.gov/jpeg/PIA08447.jpg

In the vertical view, Zeta looks a lot like an old crater, yet with no significant rim features visible. In the horizontal view it has a substantial vertical component. Stu's image shows some interesting "ringing" details which I hadn't seen previously. I'm led to wonder whether Zeta is a mound rather than a crater, which brings-up interesting questions as to the geological process which might have created a mound in that particular location.

[djellison]

A bit OT, but did we ever find an "unannotated" version of this hi-res Victoria image, PIA08447?

--Bill

Nope. I asked around, but we'll have to wait for that MOC image to hit the PDS.

Doug

[Bill Harris]

I didn't recall hearing about a "clean" hi-res image. Too bad, but we can work with what we've got.

Stu, there is a cornucopia of fine detail on this image. Not only can you see several areas of broad, low relief (which I imagine are pre-impact topography and buried craters) under the ejecta apron you can also see many muted and eroded impact craters on the ejecta blanket, presumably post-victoria impact. Can crater-counts be used as a accurate clock on Mars? I don't recall. Of equal or greater interest is the detail in the "bowl" between the rim bluffs and the dune complex. I can spot a couple of craters as well as a hint hummocky terrain expressed on the bowl surface. This area is clearly fresh and new but is showing active erosional-depositional processes.

I'm looking forward to this next leg of the Traverse. These ripples aren't dead and the winds are not still.

--Bill

[centsworth_II]

I didn't recall hearing about a "clean" hi-res image. Too bad, but we can work with what we've got.
Can crater-counts be used as a accurate clock on Mars?

As I recall, this question opened up a real can of worms a few months back. I understood little of the debate, but I get the impression that crater counts to determine age work best (or only) with large, unambiguously primary impacts, and over large areas. I expect that the relatively small craters around Victoria are caused mostly or entirely by secondary impacts.

[algorimancer]

A little more info on the Zeta feature I mentioned a few posts back. It is about 40 meters in diameter, a bit larger than Beagle. As viewed from the Sol 883 position its edge stood about 1 meter above the surrounding annulus. In the PIA08447 image, which is illuminated from below (west), Zeta shows a distinct shadow to the top (east), and hilighting to the bottom (west), but no corresponding illumination effects in the interior (no internal shadow of a crater rim). No other crater on or near the annulus shows these effects, including Beagle. Anyway, here's a zoomed-in and contrast enhanced image.

[Stu]

Maybe Zeta's an old dust-covered crater ("ghost crater"?)? There seem to be a few of them in these here parts...

Ghost crater?

[fredk]

To me Zeta appears to be just a very shallow sand filled "ghost crater". Any hint of shading on one side or the other in the orbital image could easily be due to intrinsic albedo variations.

From the point of view of Oppy on sol 883, the west rim of Victoria is directly behind Zeta, and I think all we're seeing in the pancam images is the rim of Victoria behind Zeta.

One metre of vertical relief is a great deal in this flat territory! Had Zeta been a 1 metre high mound, it would've been much more obvious on the orbital map.