http://hirise.lpl.arizona.edu/nea.php


Rover tracks at Victoria
http://hirise.lpl.arizona.edu/PSP_004289_1780

The subframe from the Newton Basin image is one of the most spectacular Ive seen, a geologist's paradise:

http://hirise.lpl.arizona.edu/images/2007/..._1410_cut_b.jpg

Oh to get a rover in there! (difficult, obviously, givern the slope and hummocky terrain!)

P

Is it just me, or does the rover track image look darker than the other Victoria images. Maybe it's the dust storm? I really don't have any idea (I've been kind of out of touch for the last month or so, I've only recently got internet set up, and I've been kind of busy recently...)

It does look very different to the previous images of Merdiani, it's very noisy/grainy too.

Could it be longer exposed than the others? - In order to make the tracks more visible.

It even seems to me Oppy was just driving during the exposure

Click to view attachment

MAY simply be the long wavelength channel, where the dark, relatively blue "sands" have more contrast with compressed redder dust in the tracks (sand grains pressed into the soil, like blueberries?)

In that image PSP_002620_1410 there are some odd looking craters that show similarities (see image below). Could it be that the three craters got their look by several simultaneous impacts by meteorites that breaked apart just before they hit the ground?

Looks also like they had could start like the group of craters leftmost, but then someone had practiced the shoot here

(click for full res)

Those are interesting. 3 craters all about the same size and with virtually square rims, in the midst of lot's of other craters with rounded rims. Typically a polygonal crater is due to impact into pre-fractured bedrock, like the Barringer crater in Arizona. Mostly what I've seen on Mars has been hexagonal craters, though Endurance was squarish (if I'm recalling correctly). In this case I would speculate that the round background craters pre-date the square ones, and that the surface was subsequently modified with the formation of an evaporite layer near the surface, and the square craters are impacts into this layer. Of course a less likely alternative would be LGM archaeological remains

If only the building bricks wouldn't be that wide scattered.

Endurance looks to me too more hexagonal. Could hexagonal or squarish be depend on the impactor size (energy) or maybe due to the layer build up itself?

One of the squarish crater (bottom right) in the composition above looks rather fresh. What do you think from which direction hit the impactor the ground?

Would you expect to see SQUARE uf0's flying out of square craters?
<you may strangle me now....>

p*ramids i tell you, P*RAMIDS!
anyway, enough of that...fascinating stuff! are there more earth analogs?

Where's that picture of the glass p*ramid in victoria crater.... with the smoke coming out the top?

I noticed that in several recent pictures.
For example look at this one at full resolution: http://hirise.lpl.arizona.edu/PSP_004097_2185
Very grainy.

Could be:
1. Dusty atmosphere lately.
2. Cloudy lately.
3. More CCD problems lately.

I hope it's not number three.

One hopes HiRISE will soon revisit the Victoria Crater area. We have a rare opportunity to record the effect of a documented dust storm in obliterating known surface features - namely Oppy's tracks, as well as the "dark streaks" on the northeast side.

Did anyone notice _white_ streaks southeast of Victoria, Endurance, Eagle and almost all minor craters in the plains north of the etched terrain? Endurance looks almost like a comet! Another crater near the southeast corner has a longer yet white tail, as well as black areas north and east of the crater, somewhat similar to scaled down Victoria.

I'm not seeing what others are seeing in those "square craters".

The one in the middle bottom doesn't look square to me at all -- it looks more like a clover-shape, which could be caused by multiple impacts in nearly but not quite the same place, all of which have since been filled in by sand.

The one in the upper right falls between two parallel lines of outcrop, but to my eye the shape of the crater between them is as round as any of its neighbors; again, with much of its outline obscured by sandy infill.

The right-hand bottom one looks to me like an ordinary round crater, part of whose rim has collapsed. There is a straight feature to the left, but I'm not convinced that it was formed by the crater impact.

Clouds and dust are factors, but most of the noise that you see in the more recent releases is due to calibration issues. In order to counter act the problems with the CCD electronics we're heating up the electronics a few more degrees. This results in larger dark currents, and hence some of the more recent images have more noise in them. By and large these problems can (and will) be addressed via improvements to our calibration algorithms, but the improvements haven't been implemented yet. We'll be kicking off a large reprocessing effort in the not too distant future that will address this problem, and there will be new versions of most of the data that we have released so far.

Good to know that someting can still be done about the noise.
But will these improvements to the calibration algorithms really remove the noise, or just act as some sort of blur filter to smear out the noise?

I also noticed that the 'vertical lines'-artifacts are more noticable in shaded areas. (see picture).
Is this also the result of calibration problems? Is the S/N ratio for the bright terrain high enough for the current calibration algorithms to work, but not for the dark surfaces?

Well, noise removal is usually done at the pixel level, meaning that you won't generally see smearing from removing systematic noise like the dark current. Generally speaking a bad noise removal algorithm will either not remove enough noise or actually add more noise to an image making it more "grainy" rather than smearing out the image. We're trying to avoid the use of smoothing algorithms for noise removal since those can smear things out a bit, although in our tests, we've found that smoothing doesn't seem to smear things out much at all, so if it comes down to it, it is option for extreme cases, but smoothing isn't part of our current plans.

The vertical lines are affected by the calibration problems, and there are some additive and multiplicative systematics that can make them more apparent (especially when you throw in the need to match the signal levels of the different CCD's). Generally, the lower the signal to noise the worse the current calibration works, although you can also see vertical striping in images were the signal to noise is still ok, but the image itself is rather flat. In these cases there isn't much contrast between the image data and the striping so low level pixel to pixel differences tend to be enhanced in these images.