A little late but here is a panoramic view around Erebus taken on Sol 631 with the L0 navcam.

Watch the dunes.

jvandriel

And here a panoramic view of only the dunes around Erebus.

Taken on Sol 631 with the L0 navcam.

jvandriel

Oppy drove again on sol 639; just a few meters south.

http://nasa.exploratorium.edu/mars/opportu...44P1214L0M1.JPG
http://nasa.exploratorium.edu/mars/opportu...44P1315L0M1.JPG

Expect more IDD work during the weekend.

Opportunity's Rat still working on Sol 639.

jvandriel

Or, based on a crop of Dilo's most excellent vertical mosaic, she is now just below the "d" at the dark cobble area.

--Bill

and here is the result after brushing on Sol 638.

jvandriel

I've been thinking about familiar size references for these smaller concretions...

The largest one in the group on the upper right is just about exactly 1mm (33 pixels) across at its widest. This is about the size of a poppy seed. (Oppy seeds, perhaps? )

Many of the concretions still embedded in the evaporite fall into a range of 0.3-0.5mm (10-15 pixels). The first thing I think of in this size range is the diameter of thin mechanical pencil lead. But since that's only circular in cross-section, perhaps that's not the best analogy. Any other ideas?

There seem to be even smaller embedded ones, but in most cases it's hard to tell if they're truly smaller or just not as exposed.

I am impressed of this outcrop so white and clean. It looks like a marine rock due to its clean surface and light color. It is strange for me to see so white sediment rock.

Rodolfo

>I am impressed of this outcrop so white and clean.

The outcrop looks white because that is an L2-filtered image (red-IR, 750u) and clean because it's windy out there.

The bedrock in a "visual" (L5, green @ 530u) image looks darker. And an L257 color image looks red-biased.

--Bill

(non-geologist)


I don't tend to follow Opportunity as closely as Spirit, but when I viewed Tesheiners Rear Hazcam image I noticed what could be interpreted as a crater. It is probably most similar to the "heat shield," crater. Naturally I also noticed all the cobbles scattered around.

IMHO: It could be a secondary impact crater. The cobbles could be collectively guilty because they are hanging around the general area. It's just a suggested interpretation of the evidence.

POSSIBLE SECONDARY ( Shallow or Spalling ) IMPACT CRATER

SOL639-R-HAZ-crop-flicker.gif
WARNING File Size 607 Kb

Click to view attachment

Good hint.

Now , I have the curiosity about how the black and white pictures can be transformed to their color spectrum like Red-Blue-Green. That I have seen in numerous nice pictures (specially of Spirit's surrounding passage). I seemed that these pictures were digitally manipulated...

Is it done by adjusting the colors generated by the Photoshop or alike tools or not?

Rodolfo

>Now , I have the curiosity about how the black and white pictures can be transformed...

The short answer: a 24-bit color image consists of three 8-bit "grayscale" images, each assigned to a Red channel, a Green channel or a Blue channel. In the RAT image above, we have an L2 (red-IR), L5 (green) and L7 (UV) 8-bit images combined into a 24-bit RGB image. I used Paintshop Pro.

Let me work up a detailed reply and put it in the "Tech and Imagery" Section, if it already isn't explained.

--Bill

A 360 degree panoramic view around Erebus.

Taken with the L0 Navcam on Sol 639.

Almost at the crater rim.

jvandriel

A panoramic view of a rock.

Taken with the Mi on Sol 641.

jvandriel

The last 2 images are down and here is the result.

A panoramic view of part of the bedrock around Erebus.

Taken on Sol 634 with the L7 pancam.

jvandriel

Wow - nice view of Endurance and the heat shield - all the way from Erebus, on Sol 632! Taken just before Olympia.

1P184286322ESF63__P2651L6M1.JPG

The above picture is incredible since it is very plain for a very extent land. The ripples are very uniform and also the Tau is pretty good so the sky is perfectly clear for 2-3 kilometers.

Rodolfo

That partial-frame Pancam was taken just before the first panorama of Kavalrita. I found it this weekend looking for post-dust storm horizon images. Attached is a 4x vertical exaggeration of that image; the red arrow shows the location of Eagle Crater.

--Bill

Opportunity still between the dunes around Erebus.

Panorama taken with the L7 pancam on Sol 642.

jvandriel

love the new pics of the dunes up close..
wonder what causes the dunes to have that "look"
dunes

Wind....

Yeah, I know, the obvious, unhelpful answer, but true anyway.

They probably took the photos with the sun at an angle to accentuate the surface variations. It looks impressive but I expect they are all aeolian features.

Whoever is studying the dunes on Mars is probably drooling over the photos as we "speak"

Has anyone tried enhancing the pancan images toward Endurance to see if any dust devils are sneaking by behind Oppy?

Here is my first attempt at putting an Oppy pan together - The full Olympia sol 634 pan in colour.

Try as I might I can't get the horizon to quite form one continuous line, Oppy pans seem much harder than Spirit's (I can't get sub-pixel stitching accuracy ) It'll have to do for now though.

It's half resolution to bring it into the realms of attachment size - I'll try and find somewhere to put the full res version tomorrow (when I'm not connecting through dialup). Along with the Spirit East Basin pan that has been requested in the Haskin ridge thread.

James.

I have enclosed a cropped picture from sol 642 (jvandriel) where there is a high concentration of dark stones. I would like to inquiry since it might be of much interest because these must be of different composition than the bedrocks. Maybe, these are oxidized rocks by some bacteria or by some kind of the chemist reaction between the water and rocks.

Rodolfo

About the surface form of the ripples has attracted my attention since it is not normal to my years of experience on dessert surf.

Normally, the ripples have smooth surface with mini-waves just in the opposite to the wind prominent direction. The upper of ripples is rugged/wrinkle and there many furrow going from top to down (gravity direction). I think that that part of these sand surfaces were altered by something by under surface. It might be by the product of water sublimation. The other possible hypothesis is that these ripples have condensed some tiny water during the winter term and these were sublimited on the summer term and this process is cycled over ..ions years.

The above words are of *No geologyst knowledge but well know of dessert place*

Rodolfo

Correct me if I'm wrong, but isn't it the case that there have been absolutely zero dust devils observed at Meridiani? In any image? Or from orbit?

It's my understanding that dust devils only form in regions where the topography causes the winds to curl in on themselves -- mostly within large craters. And they leave visible tracks. None of these conditions exist at Meridiani.

Now, straight-line winds, that's another matter. There seem to be plenty of those at Meridiani.

-the other Doug

How close is Opportunity to the high point on it's treck from Endurance to Victoria? Has it reached that point, or is it past Erebus?

Now, Oppy is approximately on the north-west side of Erebus' rim.

Rodolfo

But where is this in relation to the "mother of all panoramas" high point along the path to Victoria?

As I have seen previous posts is that the Victoria Crater is at the higest point of all way along from the Eagle, Endurance and Erebus craters. The Oppy rover, on its way, goes up a little, perhaps fews tens meters higher than its landing place.

Below, at the bottom line of picture, you can see the surface elevation of the Oppy's route. The mother of all panoramas might be in few hundreds meters before arriving the Victoria crater.

http://www.unmannedspaceflight.com/index.p...ype=post&id=659

Rodolfo

... or in other words, we should wait 'till being halfway between Erebus & Victoria.

imho, the 'coagulated' look of the dune surface I think owes to these superficial featrues not being composed of coarser sands, but of mostly dust, which should tend to stick together more than sand, especially with salts and moisture or static conditions, therefore, there would be areas where it doesnt collapse as the slope passes 45 degrees inclination, this might tend to allow some areas to stay steep while weaker areas slump and blow away leading to the coagulated 'puffy' look as the dust sticks and builds up and eccentuates these intial features. i bet if oppy cuts into those areas there will be higher ratios of smaller dust particles in them.

Yes I agree, I have not seen a greater slope than 30-35 degree if the land is purely of sand grain. That is due to the sand cannot remain on the same surface after that steep degree due to the gravity and also of its very low friction factor and low cohesion properties among grains of sand. It is specially when the grain is dry. But if it is somewhat wet, the slope degree would be greater.

I hope that Oppy would approach to these tall ripples to understand better about its tall and steep formation of sand.

Rodolfo

This is the "north erebus" dunefield, the one that Oppy had to drive north-then- west to go around. They are unusual because of their size, and now we see structure, and possibly composition.

Attached is an L456 color composite of this site. It shows that the windward side is ''armored" with blueberries (blue color) and the downwind side is likely evaporite dust in the wind shadow. And, seeing slumps down to evaporite dust, the core of these dunes may be evaporite dust. Why are these large dunes here? I'd suspect that there is an upturned lip crater or a rubble pile (ejecta) that has disrupted the wind flow and caused dust/sand to be deposited.

--Bill

I noticed that feature, too. I might be jumping the gun here, but I'm thinking that it might be related to the structure that formed the Mogollon bluff. Attached is a 5x exaggeration of a pan of the area, which shows some interesting details of the bedrock.

--Bill

Nice catch, Mike. I was looking for dust devils in those, and totally missed that.


That drift caught my attention too, as its surface morphology is different from the others we've seen. I couldn't make my brain "see" it properly. It appeared differently in the different filters. and that R2 just looked "strange" to me. Some of the topography seemed inverted in that IR image, as compared to the other filters. The color image Bill provided overcomes that problem, since it doesn't use that band. I think the best view of that drift is a 3D anaglyph, like this one made by MMB.

Edited to add: It's still a curious drift...


I was wondering about that too, if I am thinking along the same lines as you. What if the DDs on Meridiani are more transparent than those on Gusev? A good point has already been made about the general lack of surface roughness in the region, but it might be worth the effort to grind those pixels to see if anything is there.

Thanks. "Hell of a view", that's what I was thinking of. I'll be looking forward to it.

Hi Bill, I noticed too these strange dune yesterday... I made a color version using different filters (R1+R2) and obtaining similar result, it stunned me because illumination seems completely different in the two images, now I understand why...

forgot attachment...

A 360 degree panoramic view around Erebus.

Taken with the L0 navcam on Sol 645.

jvandriel

A panoramic view of some bedrock around Erebus.

Taken with the L7 pancam on Sol 646.

jvandriel

This image is a polar projection of jvandriel's great new panorama of the Erebus rim area from sol 645. I did a bit of cosmetic work on the horizon first.

Phil

Click to view attachment

Beautiful polar projection, Phil.
Always from Sol 645, here is the stretch of R2 PanCam images (about 50 deg horizontal field)... Any hypothesis on possible future path?

Another panoramic view of the bedrock around Erebus.

Taken on Sol 642 with the L0 navcam.


Phil Stooke,
the cosmetic surgery is oke. It makes better polar projections.
Sometimes Autostitch does not match the horizon very well. ( see earlier discusions )

jvandriel

This is an amazing demonstration of just how flat this region of Meridiani is. The dark layers in exposed rims and associated dunes are barely poking above the ground, yet we've been able to go back to pans from the rim of Endurance and identify these dark features from so far away.

Yep, it's flat as a peneplain (which I guess might still be applicable in an aeolian setting). But you've noticed that the Burns formation surface is developing rolls and high and low places as we head south. Lots of changes.

--Bill

Here's mine:
- Drive directly to the last visible outcrop southwards
- Do a pancam survey of the dune field between that point and the dark outcrop at Mogollon rim
- IF the dunes are ‘go’ for driving, move through the dune field.
- IF ‘no go’, drive back northwest then southwest to approach Mogollon rim’s top layer.

BTW, sol 649 (tomorrow) is planned as driving day, including at least one mid-drive navcam 360º mosaic.
---
649 p0705.03 10 0 0 10 0 20 navcam_5x1_az_180_3_bpp
649 p1110.02 2 0 0 2 0 4 front_haz_mi_1024x1024x1bpp_pri56
649 p1205.05 2 0 0 2 0 4 front_haz_penultimate_0.5_bpp_pri18
649 p1211.02 2 0 0 2 0 4 ultimate_front_haz_1_bpp_pri_17
649 p1311.06 2 0 0 2 0 4 rear_haz_ultimate_1_bpp_crit18
649 p1315.02 2 0 0 2 0 4 rear_hazcam_ultimate_0.5_bpp_pri_34
649 p1700.01 20 0 0 20 0 40 navcam_10x1_az_180_1_bpp
649 p1700.01 20 0 0 20 0 40 navcam_10x1_az_180_1_bpp
...
---
And what does it mean? That this will probably be a looong drive.

I'll agree with that. Either go straight southwards, or go around and approach from the west.

--Bill

Here is a panoramic view of some bedrock around Erebus.

Taken on Sol 644 with the L7 pancam.

jvandriel