You are far too kind...
I just love the artistic freedom you guys inprint in scientific data...

Hope our artistic freedom will not make some Martians angry

Hey, as soon as they evolve past the microbial stage, they're welcome to come to and take as many pics of Earth and colourise them as they want to!

I know this request will be blasphemy for some, but...

I for one would appreciate a 10 or 25 meter scale bar somewhere on each HiRise image. The “human scale” of planetscapes and moonscapes is what has always attracted me to unmanned space flight; I love to imagine myself at the scene. Could I step over those polygonal cracks at Becquerel? Standing in a trough in the dust lake, could I see over the next dune crest? Problem is, I have to carefully read the caption or get out the calculator to figure out the scale – how much more user-friendly to have a scale bar in each image. Instant gratification!

I can imagine it...Earth's sky taken by their robotic landers being tweaked to caramel since blue is just...well too alien for some back on Mars.

Andy

I'll second that. Exactly what's been on my mind since they started coming down - but you had the courage to post it first!

I like this one, Stu (which frame is it from?)
your colorizations are getting better and better ... nicely balanced "true-colorish" hue palette,
yet not too monochromatic/casted ... just the overall brightness could be improved (it's a bit too dark)

Thanks Nirgal, I really appreciate the constructive comments and support. I finally feel like I'm getting somewhere now... I hear what you're saying about that image being a bit dark, maybe that's a glimpse into my character...!

Stu, I like dark for a medatative image. Think Mark Rothko!

Click to view attachment

Abysses! (With scale )

Click to view attachment Click to view attachment

http://hiroc.lpl.arizona.edu/images/PSP/PSP_001513_2650/

James

And here's a big one. (note this is at 50cm/pixel)

Click to view attachment

They're not abysses, they're qanats. Now we know where to look for the water.

Percival Lowell was right about canals, only they were underground.

Steve

I guess they are more romantic terms for those so inclined. I thought they were lowly "pits," but how spectacular they are. I must say that the fountain of HiRise and other MRO instrument data recently released has brought me to my knees in tears, so perhaps some artistic license is in order.

I have been trying for a couple of weeks to post some of my favorite crops from these amazing images, but every time I open a new one I find myself getting lost in a never-never land of disbelief. It is all so real, yet unreal. Polar Layered Deposits, alluvial fans, gullies... How about the mega-breccia? That one really freaked me out. Who is waiting for the MRO data from that "light-toned" gully deposit? I so wanted to point out some special places in all of them. I guess I'll settle for posting one tonight.

This highlighted color image from the pole captured my attention. It was kind of like finding an agate in the rough. It is seriously reduced in resolution, and minus a scale bar, but this is one to get in full res.
Click to view attachment

MANY thanks for the scale bars, jamescanvin!

Now I can see at a glance that the small "ganats" are the size of a backyard inflatable swimming pool, and the big "ganat" is the size of a city block.

Wasn't that easy?

"ICEBERG!, right ahead!"
April 14 1912

Could these be icebergs rising above the CO2?

Nick

That is an interesting thought, Ames. I don't know a lot about the polar layered deposits, but I thought they were composed of layers of water ice, CO2 ice, and aeolian sediments. Your comment caused me to look up the density of CO2 ice, which is reported to range between ~ 1.3 and 1.6 gm/cm^3. So, water ice should be buoyant in CO2 ice.

We know that glaciers of water ice flow at earthly temperatures, but I would assume that flow is slower in current Martian temperatures. I don't know if CO2 ice can flow, but since it is held together by Van der Waals force, it probably can.

I hope some folks who know more about these layered polar deposits comment. There is a lot of thickening and thinning observed in the polar layers recently imaged by HiRise. Much of that appears to be due to depositional/erosional processes, but some of it resembles the density induced flows seen in buried salt layers on Earth, which flow more slowly than ice. I haven't found any diapirs, but this concept is intriguing.

Another model would be that these are glacial caves and crevasses. (A more serious variant of my original qanat suggestion).

The HiRISE caption doesn't say whether the ice they've imaged is CO2 or Water ice. If the latter, could we have the kind of water flow that creates glacial caves on earth? (subterranean heating coupled with salts producing an anti-freeze mechanism).

On a stream-of-consciousness tangent, is there any research on the physical properties of frozen brines of various kinds of salts? At Martian temperatures, we could see all kinds of intriguing solids that are never solid in ordinary terrestrial circumstances.

Steve

No doubt the pits and pit-chains are something like terrestrial glacial caves and crevasses. Something that was once there is now gone. Coincidentally, the main JPL site is running a feature about some studies of moulins in Greenland glaciers.

I just wanted to clear up some potential confusion I may have caused with my earlier post. I was talking about some of the thickening and thinning of the layers seen in the HiRise image of the polar layered deposits, not the pits. Some of it looks flow induced to me.

I tried earlier to find some physical property information about CO2 and H2O ice, but didn't find much that I could relate to shear or tensile strength. Surely it is out there somewhere. As for frozen brines, I don't know.

Tumbling boulders;

http://www.awalkonmars.com/PSP_001415_1875..._crop100per.jpg

also in color from HiRise website;

http://hiroc.lpl.arizona.edu/images/PSP/PSP_001415_1875/

Nico

Those are awesome, Nico. Thanks for posting that, and for the crop.

In the first time, I think that was car tracks on the sand! Very strange how geomatric are these features.

Oh god, Hoagland is just going to LOVE these hi-res images... he was bad enough when things were blurry, now we can see all this fine detail he'll be telling people on Enterprise Mission (oh, and by the way, does anyone else hate the fact that he's hijacked the name of the most famous, most noble starship ever? It really, really grates on me!!!! Sorry, rant over!) that every tumbled boulder track was made by a golden-sailed martian sandship hissing across the plains....

I notice that some go straight but with bounces while others go in curves. I wonder if this is because most of them are flattish slabs? The straight bouncy tracks could be due to slabs rolling face-over-face while the curves are made by slabs rolling wheel-fashion on their edges.

Something to think about ngunn...though the local geometry might hold a lot of 'variables'.

Nico

Sure. It could be that the straight ones are more like cubes or irregular spheres while the curves could in principle be produced by tapered spindle shapes, but I do think wheel-like behaviour is the most likely explanation for the curves because the curves seem to tighten up as the objects lose momentum - exactly like a wheel, or coin.

I would associate the shape of the curve with the original speed when the rocks hit the terrain after falling down from "above". You can notice that the "strait one" jumped back in the air several time untill it finaly made a regular path. The "one that curve" never jumped back in the air. I've seen this several time in the mountains (I mean here on Earth ) that rocks tend to finish they fall bending their trajectory as they loose speed. That could be an explanation, it seams logical to me but, as you says they might have other variables.

I'd like to share this crop from 'Holden Crater Layers', Primary Science Phase, release #3.

A rather large portion of the actual image but still reasonably within reach for those of you on dial-up.
(~30 Mbytes)

I find the geological complexity of this image just utterly mind-blowing! But maybe that's because I'm no geologist

http://www.awalkonmars.com/PSP_001468_1535..._crop100per.jpg

Right-click 'save target as' for download.

Nico

Wow, that is amazing! Interesting how in the top portion of the image, the cracks are polygonal, but in the center, the cracks become square. What happened in the lower right portion of the image to scramble up the terrain so much?

Thanks Nico! I hope more will come from Hi-cropper volunteers like you
Meanwhile, I made this "wallpaper zoom" with some interesting features in original scale, on the right:

I wonder too, of the image linked by Nix I can see some parts that looks a bit like something I am familiar with from Earth perspective, bedrock that have been cracked and jumbled around and then fused together again so the layers can be vertical in one place and horizontal a few hundred meters away. This in the bottom right corner, it is similar to what I have seen many times in my neck of the woods.

But going left (west?) to about middle bottom we see large pieces of bedrock that have cracked and slided sideways where one piece even have created one overhang. Is it pressure from layers above that now are gone, sliding on wet, icy or muddy bedrock, or perhaps even one ancient Mars quake that caused this?

To rephrase what they say on the Hirise operation center website, this is one area that cries out for exploration by a mobile rover.

On behalf of all the many people who, like myself, can't download or wander around the huge hi-res images, can I just say how much I appreciate people taking the time and trouble to crop these monster images and post their "highlights" here? I don't feel like I'm missing out so much now. Thank you!

I'm using IRFANVIEW.

I have a major problem with trying to load JP2 files much larger than 100 Mbytes into the program. Is it a problem with my program, or do I just need to adjust the buffer size? I don't know what size the buffer needs to be for these monster files. I'm not familiar enough with the program to solve the problem very easily by myself.

Smaller JP2 files work well with the program. Larger ones just crash it. Help!

Could RAM memory by a limiting factor too? But it cannot be the only problem, because I have 500 Mbytes of RAM for my machine. I noticed that some files are over 600 Mbytes and expand to over 1.2 gigs. ...still need help.

Thanks.

I have the same problem, but it usually works if I try a second time, I have 2GB RAM.

Cant wait to see some CRISM data on the Holden crater layers!

Some other programs you can try are the ExpressView browser plugin and OpenEV, which was discussed starting with post #45 in this thread. Note that OpenEV is included in the software called FWTools, but you can install only the OpenEV subpackage from here. I have been using both. ExpressView has been noted to sometimes cause browsers to crash. That's been my experience, but it is useful. OpenEV works quite well for me.

Thanks, Dilo! Wow. Wow. Wow. The bottom right closeup with those rectangular sedimentary blocks completely blows my mind...

JP2 images, like JPG images are compressed. Lets say I open one 100KB image compressed in the JPG format, it will take up 2000KB of system memory on average.

Now we have these monster images that are 100MB from the start, and I dont know the compression ratio. But from the example above they could very well decompress into something that takes up 20 times more of the computers memory. This is the reason I gave up on these extremely huge files, since I knew my computer isnt up for the task. I guess adjusting the buffer could help, but if there isnt a lot of diskspace available the image might not open properly at all.

The released images from JPEG 2000 are all compressed losslessly. Most JPG images have some quality of loss associated with them. The result is that JPEG 2000 uncompressed images are on the order of 3 times larger than the compressed. If one day HiRISE released some images compressed somewhat, with minimal distortion the image can be much more compressed.

Also, this doesn't take into account the large black areas where no image exists. And the images are never fully decompressed to begin with. The way JPEG 2000 decoding works allows for only a decompression of a small segment of the image.

Is today a "Picture Release" day or is there a delay 'cos of Christmas? (Heading out for work in 5 mins, so if it IS a piccie day I guess you'll all have been drooling over them already when I get home tonight... looking forward to the highlights! )

The Holden Crater Megabreccia image from Release 4 is one of my favorites. I cropped an area containing some of the larger fragments, and added a scale bar and an overlay of Eagle Crater with lander (~22 meters) for another sense of scale.

As I was looking at the larger image, I noticed that my brain would sometimes invert the topography, creating a completely different impression of the geology. Most of you are probably familiar with the effect. The description from the HiRise site tells us that the illumination is coming from the north, so it is clear that these large breccia clasts are softer than the surrounding matrix, and have eroded to become depressions rather than elevated blocks.

I thought it might be fun to hear how others initially "see" the topography in this area, so I made the attachment containing two images. The one on top has the original orientation, and the bottom image has been flipped vertically.
Click to view attachment
edit: I was led into this exercise because one of the cropped images at the HiRise site is flipped or rotated, thus creating a misleading impression.

A psychological trick to de-invert "flipped" topography in space images (craters that look like domes, etc) is to orient the image with the real direction of illumination from the top, and to actually position a light source "above" the picture if just orienting it so light is coming from "above" doesn't work.

Hmm, a psychological trick? Are you suggesting a real light source above my monitor? I never would have considered that. I have looked at that image so many times that it changes every time I blink.

That's exactly how to do it. Point your finger at the screen, make a shadow, and POW! those Martian Domed Cities become, er, craters!


Bob Shaw

"Are you suggesting a real light source above my monitor? "

Exactly. It's a desperation last trick for images that won't de-invert. Usually, just orienting the pic so the pic's illumination is coming from above -- as seen by the viewer -- works, but some pics are "recalcitrant"

I really tried to make that work, using various light sources at different positions. But I don't see how I would create the shadow of my finger on my bright screen, short of using a blinding light. It sounds like a good idea, though.

In keeping with the theme of illusions, here is something different. When I first saw North Sinus Meridiani Landforms from Release 6, I knew instantly how it needed to be "enhanced." The f@ce and pyr@mids of the Cydonia region are nothing compared to this place. Kick me, if I am bad, but I thought we made allowances for artistic impression here.

The detail that HiRise is able to capture is amazing. I've named this image, "Mars...Land of Change."
Click to view attachment

What helps is the way your finger (or try any other object) is illuminated from the light above, and the shadow is not necessarily needed. Expecting a light source from the top is wired to our brains, naturally.

I've never struggled with this, once I read "illumination from the left" - I'm fine...BUT

I've NEVER been able to watch the Apollo 11 landing and see 'craters' on the surface, it's always been domes....it really annoys me

Doug

Nice joke, there CR. I almost didn't notice the Jefferson Nickel until I saw the words "trust" and "liberty" on the crater rim. Oh, and the FDR dime makes for nice "change" also...

First of all, A Happy New Year to all of you

Let me share the latest finding of my "HiRISE Mars Sightseeing Flights": a colorized crop of the "Ius Chasma" image of the PSP5 release (original image here)
Included is a 50-meter scale symbolized as the shadow of an "imaginary" passenger-jet, just for a better "sense of scale" of the
scenery ...

Click to view attachment

(usual disclaimer: the synthetic colors are based on "real-color" palettes and guesses about
probable surface composition (i.e. "blackish" dark basaltic sand dunes with light colored, more reddisch/yellowish exposed rocks etc.)