Thanks for posting this, but could you provide the URL link for these?

THX.

Carrick

Awesome job! That should put to rest any questions about the origin of the Beacon as being from the near rim.

Pretty wild looking, Prometheus! Looks like water action to me (seeping water from the crater wall depositing dissolved minerals as it evaporates?), similar to what we see here on Earth in

If people are correct that there is water stored under the surface of Mars, then you should see evidence for it in exposed rock faces such as are found at Victoria.

how do we go about collecting a little happy for Rakhir. I'd pop $5US for a nice bottle of champagne for him (& I didn't even participate in the "contest").

That's quite clever!

Are you trying to start another near-rim far-rim argument?

Given the nature and scope of the work at Victoria (70 m deep crater, 750 m diameter, 2.5 km circumference), I think it makes perfect sense for them to refine the software and fully test it before proceeding to the crater. In addition to the usual Mars strata studies, there is evidence of dynamic processes at work, such as the apparent gullies. It may be a while (a year?) before the "good science" from this massive & complex target is fully exhausted.

From common sense and things other people have said, there is a very low risk of losing the craft from the software update. You also certainly want the software fully tested and debugged before proceeding to VC. There is likely a much bigger spacecraft risk, once at VC, from a navigational error than from delaying the arrival by a week. Also a bigger risk, I would think, from inefficient exploration, since it may well be the case that the lifetime of the craft is reached during the exploration of the crater. Improving how rapidly targets can be reached & studied (touch & go versus go & touch).

As usual, once we learn more about what the rover team is thinking, we realize just how incredibly talented these guys are! Awesome work.

Do you know if they can still reboot with the older software if there turns out to be a problem?

I haven't seen anybody else talk about this, so pardon if this is duplicated information:

Steve Squyres was on NPR's Science Friday today and talked about Oppy's journey to Victoria: He predicted that Oppy would reach the crater rim late next week at the earliest.

The reason is that they have apparently completed the unlink of the new software and will be spending some time doing a shake down on it. Also they are very interested in the composition of the material on the annulus, which they think may have been blasted up from deep in the crater.

Here is the XML link in case you're interested: http://www.sciencefriday.com/audio/scifriaudio.xml & here's the ITunes subscribe link: http://www.npr.org/rss/podcast/podcast_det...?siteId=4822271

Thanks, Pando! What a great graphic!

This type of serration of the front of the rim is of the sort that some of us (notably far-rimmers) were speculating would be present.

If you note that "tabled" appearance on the right-hand side of the far rim, I would presume that it is from the raised lip of the mini-crater at that location. I've also been speculating for a while that we've been resolving that raised lip of the small crater on the far rim of Victoria in some of the images of "the" beacon (see for example this link.)

Actually, it seems to me like the near-rimmers have a pretty firm hypothesis that should be testable.

They are claiming based on trig the existence of a promontory or other similar feature at the ``beacon'' position on Tesheiner's map. If we can identify a unique feature at that position when we get close enough to get a detailed image of the northern rim, then they would have been proven right, otherwise wrong.

If there is no near rim feature at the ``beacon'', then to me the most likely solution is a gap in the near rim through which we are seeing different features on the far rim as the rover shifted positions over time.

I'm an admitted newbie when it comes to working with the Pancam Data Tracking Web Interface, but does this "unexpected sequence" on sol 904 have some bearing why we don't seem to be getting any new data?

Great mosaics as usual! I thought exactly the same about going left. This looks like the best direct path to me:



Not that I'm back seat driving or anything.

Oops! You're right.

I guess this must be that small crater to the south?

***Thanks to Ultrix for pointing out my error! I misidentified another feature on the horizon as the Beacon.***

These comments are in error, though the stacked image (whatever it is) should still be ok.

Can you remind me how you calculate this for your image?

Our eyes play tricks with noisy images (esp. those that have been handled unkindly by JPEG compression). I think it could go either way. Hopefully we will know soon.

I took your image & blew it up some, rotated it with my image, then plopped the boundary that I obtained from my newer image onto your averaged image. Here is what I see:



What I see is consistency between the two images for the location of the rim, but that is about it.

I don't think we can conclude that the beacon is a tall prominence, as is perceptually suggested by your image. Nor do I think it's plausible, based upon the satellite view of Victoria Crater, simply because a shadow should have been clearly visible from such a feature. Finally, as I noted earlier, there simply is no identifiable feature with the colorations observed on the near rim, at least at the location that Tesheiner has triangulated to.

That's what started me wondering whether it really is a prominence at all, or just background images filtered through a closer-ranged notch in the rim wall.

Certainly you're welcome to disagree with me about all of these conclusions, but that's the best reading I can get from what data we have in front of us. Hopefully, we will soon know the truth!

The issue isn't just noise level... it's how much contrast you have between the sky & the crater rim. You don't appear have enough contrast to resolve the crater rim for the conditions in which your image was taken.

The VC crater doesn't appear to be resolved in your image at all, except for the "beacon". Certainly the beacon stands about the foreground, but that doesn't prove very much. The images I was referring to were much earlier ones, where we were maybe only getting a single pixel.

Here is essentially the same viewpoint, with the rim of the crater visible.



Clearly the beacon isn't jutting above anything.

[Edited to fix the attachment.]

I don't think it requires much of a coincidence. I'm suggesting that there isn't a real prominence on the back rim, and the "keyhole" is just allowing you to see the otherwise obscured wall of the back rim. So it's not a "feature".. it's just light reflected from the higher albedo of the interior wall of the crater generating a "glow through the keyhole."

The prominence shape (I think) is nothing more than CCD or JPEG bleed, or possibly glare due to dust on the optics fattening the glow through the keyhole.

Actually, it just requires that the top of the far rim be below the maximum angle of inclination for the front rim, and above (on average) the minimum angle of inclination for the near rim, after correcting for the curvature of Mars. See the enclosed figure:



From a quick back-of-the-envelope calculation, the far rim will be reduced in apparent height by a distance,

h = (rfar^2-rnear^2)/(2*R)

where rnear = distance to near rim, rfar = distance to far rim, and where R = 3.390e6 meters is the radius of Mars. Given that the diameter of the crater is 750m, this gives

h = 0.5 m when rnear = 2000m
h = 0.3 m when rnear = 1000m
h = 0.2 m when rnear = 500m.

Since the relief of the crater is expected to be pretty small, probably only a few meters at maximum, the curvature effect should be pretty important, and unless there were a significant height difference for the far rim, it would never broach the top of the near rim.

Perceptually, I know, it seems especially from early images that the beacon was above the height of the rim. However, I think this is just a result of bleed-over from the highly saturated pixels containing the beacon. The nearer shots, like the one I included above, seem to suggest that the beacon height is roughly the same as the height of the Victoria Crater profile. The pixel resolution is so poor (esp. for those of us using JPEGs) that I don't think you can say much more than that.

Beyond the fact that we can see the beacon, really it's so poorly resolved that it would be hard to argue that we can really say whether it stays at exactly one height or another. The only condition for viewing the far wall would be the height of the far rim be tall enough (including the curvature correction) to peak above the dip in the near rim.

Actually, it just requires that the top of the far rim be below the maximum azimuthal angle

Sorry that it took me a bit to figure out what you meant. Actually if you trace out the horizontal line, Victoria crater appears to rise above it (the dashed line is my rendition of the horizon):



Further if you trace out the top edge of the crater, the beacon does not (to me at least) appear to jut about above the top of the crater (the solid blueish line). I've also drawn in a red line showing what I consider a plausible profile for the near rim based on a "keyhole" hypothesis.

I'll admit these reconstructions are very risky given that we are starting from a blow-up of a JPEG. But it seems to me to be as reasonable a hypothesis as a near-rim prominence...

Actually, I'm not suggesting we're seeing the same part of the far rim, but rather different parts of the far rim at different times through a depression in the near rim:

I've annotated a version of your figure to hopefully explain better what I mean:



My point is that the "beacon" is poorly enough resolved that currently we can't tell if we're seeing the same features or different ones with the two views. The background of the crater remains relatively fixed, and it is the parallax of the depression on the near rim that is causing a shift in the field of view through the "keyhole". (So the parallax measurements simply give the location of the keyhole, through which "white light" is shining.)

The only reason I find this "more likely" is that to the extent we can distinguish any features, they appear like classic Mars "white cliffs", and there simply isn't any detail on the near rim consistent with this. The only way we could distinguish the two hypotheses would be to resolve enough features in the "beacon" to track the features of the beacon, and not just it's location.

Why is this a problem for viewing part of a raised far-side rim through a keyhole?

Anyway, I hope I've made myself a bit clearer!