For a long time I have been curious about the fabled, "Hell of a view" location. Although I was expecting it along with the rest of you, I wasn't actively looking for it at the critical time. So, I decided to look back to define its location. It appears to me that "Hell of a View" (HoaV) was topped by Opportunity on sol 785. It is difficult to pick exactly when she began to descend from HoaV, but it was between sols 787 and 814. If anyone wants to count pixels to more precisely define it, be my guest.

I am attaching a montage of horizons, screen-captured with MMB at a constant magnification. It is captioned to note how the appearance of Beagle crater changes with respect to the horizon, as Opportunity changes in elevation. I have another montage combining Phil's most excellent route map with a stretched version of the original HoaV profile. Stretching the profile between Eagle and Beagle confirms a location for HoaV in about the same place. I just do not have time to upload it on dialup tonight. I'll post it tomorrow. Sorry.

I thought it might be fun to see who, if anyone, recognized the event when it occurred. Kind of like a reverse poll, where it is too late to hedge your bet. Searching the forum for relevant posts is difficult, but I came up with a couple of links. I suspect there may be one or two comments that I missed, so post your links here.

As we left Erebus behind, RedSky asked where HoaV would be. Phil and centsworth_II made pretty good predictions for the time. http://www.unmannedspaceflight.com/index.p...amp;#entry45719

On this low-fi view of the forum, I discovered that Chmee seems to have recognized the topographic topover on April 14th, 2006. A little later Dilo agreed, and noted that Opportunity was descending. That was around sol 789. http://www.unmannedspaceflight.com/index.p...;f=2&t=2417 Their recognitions are the best I could find, and so far, the winners.

My gut feeling is that HoaV never happened. HoaV to me means coming over a rise and having the view take your breath away. Kind of like when we peered into Endurance for the first time. I was expecting from the profile that we were going to look down into a valley with this monstrous crater taking up a good chunk of the real estate. Maybe not quite as dramatically as viewing inner basin from the top of Husband Hill, but you get the idea. When you have to go back and count pixels on the horizon, I have to say it wasn't a HoaV.

Brian

Ho-hum of a view perhaps...

Chris

The Heck of a View was rather underwhelming, wasn't it? At the topographic high on Sol 785, the view back to Erebus was non-existent and the view forward to Victoria was nearly that.

I expected to see Erebus with a backdrop of the "North Erebus dune field" and Endurance on the horizon to the North and a greatly foreshortened Victoria surrounded by a dark and smooth ejecta blanket to the south.

At least we'll have good views once we get to Beagle and Victoria...

--Bill

To be honest, I never reckoned the MOLA altitude figures were going to be accurate enough to provide anything other than a sort of CEP for the high point. A guide to the area generally being about as high as it would get, but that'd be it. Then, if you were at something other than the true 'peak', you'd barely see anything. And that's what happened!

Bob Shaw

Let's look at it this way. For those of us expecting an enternal reward some day, a really nice view would be part of it. Those of us who were naughty and don't get our eternal reward, we get a "hell of a view".

Ah, I tuned in to this discussion thinking that we had started discussing this (Victoria is finally fully visible as a crater!):

<img src="http://static.flickr.com/65/185713976_d454b027a3_b.jpg"><img>

For me, that definitely qualifies as the helluva view/takes my breath away moment.

Oops.

Let's try that again:

I was unbelieving... are we actually looking down into and seeing the inside of the hazy far wall of VC here? are we already almost there yet (or is VC really that big)?

Here's another good shot at the upper left.

the dark stuff of the Apron just ends abruptly, as if it drops off into the void of VC... makes The Becon look to be on the FAR SIDE!! if thats indeed it (ive lost track) ...but im still skeptical. it must be some kind of trick... if not, then it sure is one HECK of a View!

I may be completely off but aren't those twin peaks on the horizon supposed to belong to the north rim of the big crater on the ESE ? I think we're not looking at VC here, which should be a little more to the right in those pictures, but the north of the apron slowly rising toward the real rim of Victoria, and what you describe as the internal far rim should be the plains behind. No ? I could be wrong and that wouldn't be the first time

No, I think that's just the far horizon/landscape. VC isn't *that* big.

But I think the inside of the VC crater is becoming visible - there is a thin sliver of a vertical wall visible just under the dar streak you mention. It looks sort of like Endurance creator looked from the landing spot.

Remmeber the the VC crater is sloping away from our viewpoint, so it is only now that we are getting close enough to start seeing into it.

Sounds plausible. 200m high hills should be visible from over 30km.


Of course, if we had the exact distance & the height above the horizon in pixels then (assuming the horizon is perfectly flat) we could calculate the height of the crater rim. Any takers?

Ok, i was completely nuts, dont listen to me. If i had pulled back to see a context image, and then consulted Teshiener's latest map (where would we ever be without him) it shows VC should be directly behind CC (er, Beagle that is). So it looks like were not higher than VC at all. As expected, we cant see down into it at nearly that high of an angle. the dark apron drop-off area is the top of the east apron edge contrasted against the lighter plains farther behind. Now if only Oppy had a derigible sky-cam, then we might be able to get the image i entertained we might have.

Oh no, you're not. Those are the twin peaks of that big crater to the SSE. Most of Victoria crater was not visible in the sol 873 pancam set. The darker wedge just below the horizon and growing from left to right in stevelu's images is the southeastern side of Victoria.

Well, it did actually happen, but your point is well taken and worth mentioning. It really wasn't the view that some were expecting. The MOLA data that created the map that the profile was derived from had relatively widely spaced control points. So much detail is missing, that the map and profile are misleading to people who are expecting to see things like Victoria's rim in the data. That level of detail is just not there.
Yeah, I can't argue with that. That's probably why it mostly escaped notice in the forum at the time.
Underwhelming is probably the best one-word description. Though the view from those "lofty" elevations wasn't impressive, the identification of the actual high point was a significant event. I'm still not certain that I agree with your contention that the bedding is so close to horizontal that the elevation high corresponds to a stratigraphic one. I've seen local dips all over the map along this long traverse, but it seems to me that the average is a slight dip to the south.

Regardless of who is right about that, it would have been important for the MER team to recognize the elevation high and take a number of bedrock observations there, as we've mentioned. I checked back into the archived Opportunity updates (http://marsrovers.jpl.nasa.gov/mission/status_opportunityAll.html), and it does appear that they stopped to smell the roses more often than usual after sol 791.

_________________________

I think these are the original posts where the story of "Hell of a View" may have begun, but it might go back to an earlier post from alan. If anyone can find that, please post a link. Look here. There was a large (18 MB) pdf file linked to in the posts there. Later, a topographic map and a profile were extracted from the pdf and posted. I will add those images as attachments to at least show the captioned profile and the map it appears to have been derived from.

My intuition says "essentially flat-lying with a slight dip to the south", but unless we have accurate elevations on some sort of marker bed, nit-picker in me isn't comfy with any dip anywhere. Perhaps we'll spot something in Victoria that we can correlate with what we saw in Endurance and we can pull elevatiosn out of the hat. Hope springs eternal.

I'm hoping that Oppy won't find the end of her days inside of Victoria and is able to continue the traverse southward and downhill/downsection.

--Bill

Ok. This will be my last post tonight, but yesterday I did promise to provide a map with the stretched profile. I needed a route map going all the way from Opportunity's landing site to Victoria. Phil graciously allowed me to stitch together his two amazing route maps for this purpose. The meld is probably not perfect, but hopefully few can detect the seam.

What I've tried to do here is to take a segment of the profile and stretch it from Opportunity's landing site to my guess as to where a recent location point on the profile coincided approximately with some point on the map. The stretched profile line is on the left of the image, with arrows correlating the profile segment to the map. Because the MOLA control points are so far apart, that was almost a WAG. Obviously the profile is somewhat misleading due to the wide separation of control points. There is obviously some error in this, but I think it is fairly close, since it agrees with the ground truth.

Well, maybe that was my second-to-last post. It really is a tough call, Bill. I'm going on "gut feeling" here. To actually nail it would require going back through each sol's imagery and making measurements. That would be essentially a real pain. Let's agree to wait for a tie-breaker.

I basically agree with you on the issue of the dip, Tom. The Geologist in me says let's go with gut feelings or intuition on this, but the engineering side quips let's have some numbers to plug into a formula.

Even then it's a draw: with a southern dip, higher topo=higher section and travelling further south means higher in the section, too.

And I'm in agreement with your stretched profile, too.

--Bill

I remember this profile, but the horizontal scale is wrong (or the landing site location is wrong). The original pdf includes a horizontal scale:Click to view attachment
This indicates it's close to 20km from landing site to VC, which is way too large. The pdf looks like just a conference presentation, so it's not too surprizing they weren't careful with it.

The main point here is that we should never have expected much of a view: this profile is stretched about 400x vertically! Imagine the profile flattened 400-fold; that's how flat Meridiani is, and you don't get spectacular views on flat terrain!

As far as defining a HoaV point, I think the point is that we did reach a local maximum (a very subtle "ridge") around sol 790-810. This is clear because we could see both forward (south) and backward (north) horizons during that period, but not before or after.

South horizon (in particular VC) is visible from roughly sol 790 onwards (arguably a bit earlier) as seen in this composite: Click to view attachment
(This image is from someone on this board (Dilo?); I couldn't find the original post - does anyone know how to search for attachment names?)

North horizon is visible in this navcam shot from sol 810 (and all previous sols), but not in this navcam shot from sol 815 (or any following sols).

Therefore both horizons were visible simultaneously during sol 790-810 or so. Interestingly, I can see a correlation with the orbital imagery. Notice how in this map (from Tesheiner):Click to view attachment
the period sol 790-810 corresponds to a region with more white outcrop.

So I'm proposing that large areas of outcrop in the etched terrain tend to be somewhat higher than dark areas - this is consistent with Erebus, with dark interior and white rim. I don't recall this point being made before, but it must've been?

Anyway, this is interesting since Beagle is on a well-defined bright region, and once we're there that may give us a great view of the approach to VC.

Based on USGS' MOLA / MOC NA Stereo DEM of the area, the area traversed between Sols 807 and 813 looks to be the highest in the area, with the vicinity of sol 808's stoping point looking the most likely to be the HOV 'point' for Oppy's journy southward. This is consistant with the observations already made by FredK et al. Not much of a summit , but an observable elevation max for sure.

Below are plots I put together back at the end of March. (I don' have the time right now to put together new plots.)

Click to view attachment

and

Click to view attachment


-- Pertinax

Fredk: I'm glad to see you take an interest in this topic. Yes, there definitely seems to be something seriously wrong with that scale bar. The original pdf was claimed to be 18 MB, but was actually 1.8 MB, so I finally downloaded it. It is unfortunate that the pdf only consists of images with little supporting text, so perhaps something was misinterpreted, or maybe there was a gross error. Personally, I never was expecting a spectacular view, but I did understand that recognizing the highest topographic point was significant for geologic observations along the traverse. I was trying to demonstrate the flattening of the vertical exaggeration with my stretched profile along the length of the traverse.

It's got to be somewhere around there. My original prediction was for somewhere between 787 and 814, without counting pixels. I have since attempted to count (estimate) the # of pixels Beagle's peaks were below the horizon on various sols, and I can only "refine" my estimate to 785-810. Some of the pancams seem to be poorer in quality than others. I'm not sure that seeing both horizons is important when defining the high point, but it is fortunate that we could see a recognizable feature on one of them. Since it was such a "subtle ridge," intervening tall drifts could interfere. The southern horizon is also somewhat variable since Victoria's variable topography was affecting it. The subtle ridge might have also been a double ridge.

Pertinax: I was hoping you might show up for the party with your MOLA data and software. Plotting a profile along the actual traverse should be more accurate than what I did. Do you have any way to display a map with the original MOLA control points? I think that would be quite enlightening.

Probably the closest thing we had to "A Heck of a View" is with this by Phil Stooke from Anatolia (pre-Sol 90) in which Eagle, Endurance, Erebus and a horizon bump reckoned to be Victoria are all visible.

Not much, but defining "HOV" as E^3 and Victoria visible, it fits.

--Bill

That was a nice view, Bill. I can't resist mentioning one of my favourite views, this 5x vertical stretched pancam mosaic by Dilo from the Olympia/Purgatory II site on sol 659, looking back at Endurance and the heatshield. (Original post here.)

I should be able to do both. We have stormy weather in our area that I'm monitoring / forecasting today so I may not be able to post any images until tomorrow.

Cheers,



-- Pertinax

I think I can just make out the beacon.

Brian

That "Lookback" view has to be one of the most evocative images of the mission. It demonstrated how far our intrepid explorer had come. I was working on my own lookback image, but I can't seem to locate it right now; here is a similar image in false color looking back with the "North Erebus Dune Complex" in the right foreground. I beleive that the author is Dilo.

I thought that the view might get better "further uphill", but it turned out, this was that heck of a view we sought.

--Bill

Pertinax: I can see that you may be busy with other responibilities, but the one thing that I would like to see is a map of the MOLA control points. I'd have made it myself, but I haven't been able to locate a MOLA dataset that covers the relevant area of Meridiani. I've scoured the ftp site previously mentioned to no avail. Can you point me to it?

No, I have not been able to find the actual / true control points myself -- Back in March I looked some but could not find any (I will confess however that I did not search all day, so there are likely some holes left unexplored where they could, and likely are, still hiding).

I thought a few years ago (2001 - 2002 ish) I remember there being available for download select areas of data with the actual MOLA spot values.

Sorry for the confusion -- what I have only has the interpolated MOLA data, same as has been seen elsewhere.

(Today looks quiet so I will again attempt to create another plot of the Oppy elevation along her trek.)


-- Pertinax