[X] My Assistant

[marswiggle]

Going back again to the "beacon"'s position at the near/far rim, here is what I've got measuring some headings.

The beacon's heading is, imho, consistent with a near rim location.

Excellent work. I was preparing a post on the same theme, but you were quicker. And the quicker the better (so to say).

I only add my observation which is consistent with your results (as of my original draft):

Oppy has traveled 600 m on a relatively straight course towards the Corner Crater since detecting the 'beacon', about sol 780. All the way the position of the 'beacon' has remained virtually unchanged relative to the near rim 'bulge' and the conspicuous dark patterns around it. (See dilo's series of stretched images and Ant's movie.) The horizontal parallax of a far rim object should by now have changed about 0.7 degrees relative to the near rim (using sol 816 pancams as a scale). If the 'beacon' were on the far side, it should have moved to the right of the near rim bulge or then become obscured by it. Given that Oppy has been descending, disappearance of the beacon would be yet more probable (as Phil Stooke demonstrated).

[Phil Stooke]

Well, all these arguments seem to add up to a fairly solid case... the only alternative I can think of is that the 'beacon' is a small hollow in the near rim showing a glimpse of a distant outcrop. Changing the viewpoint reveals a different part of the distant cliff through the same hollow. I don't think that is very likely. But in general it's always good to try to think of alternative interpretations if you can!

Phil

[Jeff7]

And someone would have spotted an abyss somewhere in Arizona.

[Bill Harris]

Looking at the map, it appears that the sinkhole actually sits on a chain of something stretching in the south-west to north-east direction. Can it be related to Anatolia?

There is indeed a line of prominent anatolia-like features trending NE, as you have observed. I've looked for a message that was posted earlier message and haven't been able to find it; I suspect that it was in the missing "Victoria on the Horizon" thread. Oppy may pass near another one of these features on the way to "Corner Crater" so we may get a closer look.


I'm rocking on the fence (that is, undecided) on the location "Beacon" feature. It could be on either the near or the far rim: it is hard to tell now since Oppy's path is headed in it's direction and there is little parallax shift. As I noted earlier, we'll know in a few Sols.

--Bill

[Bill Harris]

Or _thought_ they had spotted...

--Bill

[RNeuhaus]

I grabbed this good old CorelDraw zoom tool and got a bit more detail, I guess...

http://i16.photobucket.com/albums/b14/ustrax3/beacon2.jpg

That would be the most important attraction center. Very strange to have a tall lighthouse of VC. Everywhere around VC is completely flat with only minor oscilations of no more than 1.40 meters of land with sand ripples. Then it might be a survival big boulder caused by impact VC crater.

Rodolfo

[RNeuhaus]

I am thinking and am something surprised that in Mars, the long range view does not get blur view as does in the Earth due to the thermal heat. As the Mars' weather is so cool and the air does not make less distinct or clear the long range view.

Then the blur view might be due to the low PANCAM resolution for that distance, around 1,200-1300 meters.

Rodolfo

[edstrick]

" am thinking and am something surprised that in Mars, the long range view does not get blur view as does in the Earth due to the thermal heat...."

The surface pressure of the air is somewhat less than 1% of that on Earth at sea level. I expect that refractive index is somewhat dependent on average temperature and composition, but to a good zeroth-approximation, the refractive blurring of the martian atmosphere will be 1/2 to 1% of that on Earth.

[dilo]

Ustrax, your features identifications/namimg is intriguing, but I must underline that original image quality was very poor and I made heavy processing, possibly some features could be not real!
we will see...
Ant103, great animation. Looking to this and considering also that beacon visibility is continuosly increasing (in spite of the fact that Opportunity is descending), I'm seriusly re-considering the hypothesis that we are seeing the crater interior (far rim) in the center portion of VC, as suggested bu Toma!
Look at this annotated version of !official stretch", where I outline possible far (red) and near (blue) rim contours, with some possible inner crater features identifications (purple arrows)...
I'm still not sure but I would appreciate comments on the hypothesis

Attached thumbnail(s)

 

[dilo]

Very interesting considerations on the beacon from Theseiner/marswiggle... I didn't consider parallax, I will make some checks on this soon!
Meanwhile, I suggest to concentrate the discussion on this argument on the other specific thread (Victoria Features); IMHO here we should discuss other features like "sink-hole" or the "corner crater"...

[Bill Harris]

Here I am, still rocking on the fence, but about to fall off!

You may very well have a point there, Dilo. What we are looking at is the entire southern part of Victoria's basin?!?!! I was simply assuming that we were seeing the northern "ramparts" to the rim, and the "Beacon" was either on the northern rim, or we were, by chance, looking through a scallop in the rim.

But if we were looking at that northern rampart, we would be looking at the ejecta blanket, and it's appearance would be dark, whereas the crater basin near the rim is clearly lighter toned. I'll agree with your identification of features in the rim. Note also that there are light and dark streaks from the mass-wasting ("landsides") on the southern basin wall, let's enhance contrast/etc and see if we can match these albedo features.

I hate to make "I agree" posts, but I agree.

Interesting spot, this Victoria.

--Bill

[djellison]

Well - I'm not one for fence sitting ( get a sore backside doing that ) - I don't think it's the far rim, I think it's the near rim

We'll find out soon enough
Doug

[dilo]

Doug, I would like to know why you think we are seeing the near rim...

[Bill Harris]

This base image (which was posted by Dilo earlier) isn't 100% correct, but I've annotated it to show suggested lines-of-sight that seem to support the contention that we are looking at the far rim of Victoria.

FWIW.

--Bill

[helvick]

This base image (which was posted by Dilo earlier) isn't 100% correct, but I've annotated it to show suggested lines-of-sight that seem to support the contention that we are looking at the far rim of Victoria.

The problem with this is that the MOLA data is way too sparse to use it for this - there are something like four MOLA data points within all of the area we are looking at.

My gut feel is that the parallax changes make this look like the near rim. We'll see pretty soon though - another 200-300m and it should be blindingly obvious either way.