December 27, 2006, HiRISE Release

B****r, I was just going to bed... oh well, time to put the coffee on...!

Don't be fooled by the seemingly bland "Northern Plains" descriptor. Some of these images are fascinating, particularly the polygonal fracturing and boulder fields associated with the prominent crater in the upper left of PSP_001464_2460.

thanks for the 'heads up' I was saving the bland sounding 'northern plains' for last

still no Pathfinder overhead shot! oh well...maybe next week!

I've only done a cursory surf-through, but, so far, PSP_001432_2015 ("Layers in Olympus Mons Basal Scarp") is the real gem. The variety of terrains captured in this one image is really good: craters, spurs, boulders, intracrater dunes, low-albedo mantles, and even dust avalanche scar.

EDIT: PSP_001440_2175 ("Sharp Scarp and Varied Features") isn't too shabby, either.

Yep, that O Mons shot is great, can't wait to see what our Image Mages do with that. Have to be honest tho... I know they're scientifically valuable, and there are sound reasons for taking them (MPL landing site, etc) but just for me, personally...

Click to view attachment



Only joking guys, no hand-slapping needed; I know every image is sacred and these are no doubt groaning under the weight of invaluable scientific data, but come on, be honest, you'd rather see some glorious shots of the crumbling sides of Marineris or gullies wending their way down interior crater walls too...

Yer Northern Plains = nap time......lol.

They are my favorite though to validate, they hardly take any time at all.

Keep in mind that the pictures that were released today are roughly the number of pictures taken in an average week (The actual number is probably a bit higher), so...

This looks like a series of layered drumlins (some clearly fossilized), indicating a series of Continental type glacial epochs on Mars.

http://hiroc.lpl.arizona.edu/images/PSP/PSP_001448_1735/

You had me going there for a moment, but (sadly) I think not.

For:

Linear distribution
Rocky composition
Discrete piles

Against:

No other glacial features
Scale
Distribution unmediated by topography
Distribution limited to one geological unit

I see this as a surface eroded by wind, with relict debris from an eroded layer.

We *do* see, I think, strong evidence for glacial flows in some of the new HiRise images, but I've yet so see any post-glacial features. They must be there, though, along with those shorelines we've never found...

...perhaps Mars simply hasn't thawed enough since the last glacial epoch to leave the sort of features we see on Earth.


Bob Shaw

Come on, admit it, your office party went on waaaay too long, you all had too much to drink and when you all woke up you suddenly realised you only had a handful of MRO pics processed, so you just photographed a piece of sandpaper in b&w with a big zoom lens and put those up on the site instead...

No, but I'll keep that in mind for future use...

Aeolian erosion is a given feature for any Martian topography. The question is the relative ages of the various morphologies. It is now obvious that water in one form or another has played a major role in the geology of Mars sometime in the distant past. The only question is how much of a role has it played in the recent past. Recent forms are highly influenced by aeolian processes. That is not questioned.

The problem with your argument is that this feature is not isolated nor without precedent.

http://adsabs.harvard.edu/abs/2004haom.conf...50N

So, I'm absolutely serious in my supposition that this is an example of drumlins.

http://hiroc.lpl.arizona.edu/images/PSP/PSP_001448_1735/

The multidirectional nature of the underlying composites supports my contention about a series of epoches instead of contradicting it. There must of been a series of freeze and thaw episodes to fossilized the unlying features. Wind erosion and deposition alone can not adequately explain most of the features on the new image--the forms of the features are simply not correct. But they do nicely match those forms of drumlins.

That doesn't mean that are in fact drumlins. More detailed study needs to be done for any confirmation of such an idea. But they do look like drumlins.

Hey, I just got an email from Eric (He's one of key folks here at HiROC), asking me to do a bit of commenting about Phoenix sites. Specifically, he stated:



So, basically we have alot of pictures of the Northern plains to help locate a suitable Phoenix landing site, and we're taking more due to the light failing and increasingly poor weather conditions (The weather quickly becomes poor during the winter, due to a number of factors that I don't fully understand, all I know is that only in the peak of the Martian summer is a pole easy to photograph, and as it becomes more towards fall, it quickly becomes poor.)

Right now we aren't taking any more pictures of the northern pole until conditions become more favorable, and at the end of Cycle 5 (Which takes place in the middle of January) will be the last one that we can obtain pictures for the Phoenix latitudes (Above 60 degrees north, give or take).

Oh, some of you might want to know how we keep track of this. There is a camera on MRO called MARCI, the Mars Color Imager, that comes from MSSS. It is used to take daily photographs of the entire planet Mars, which we (And the other teams) use to help us keep the spacecraft taking pictures in places where we can see the ground. Martian weather doesn't change quite as fast as it does on Earth, so the few days or weeks notice we get from the MARCI team really helps.

Pleeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeease take a pic of "my" crater on Mars, the one in Ganges Chasma that made me fall in love with the planet in the first place...

Click to view attachment

Eventually there will be a system for the general public to request locations to take pictures at Mars (I've heard that the system is being beta tested right now, but I don't have any word on that for sure. It should be out to the public soon). So, what I'm saying is, you'll be able to make the request yourself, so long as you know the location to request.

In Beta? I thought MGS (of fond memory) had a public outreach campaign years ago which allowed anyone to ask for a location to be imaged...

Bob Shaw

MOC did, HiRISE is still working out the kinks in the system. The problem now the last I heard is making sure the Database is secure (If it's not, it could cause huge problems). I think ours will be somewhat more advanced than the MOC system, from what little I've seen (I think I saw it used once or twice...)

Good points, but:

The paper you cite posits a whole range of sub-glacial features in Aeolis, not merely drumlins; some of those are, indeed, persuasive (the eskers in particular, which do appear to be 'fossilised' in much the same way as the more famous exhumed delta structures) and I would also accept the many examples of what the paper helpfully describes as 'viscous flows'. The moraines, though. I'm less convinced by - I've still to see good peri-glacial or post-glacial features.

As for the current HiRise image, some further thoughts: these presumed drumlins don't form the classic 'basket of eggs' topography, and don't have any leading or trailing edge differences that I can pick out. Nor is there any sorting of the objects which look like rather large erratic boulders (assuming we're looking at glacial features). Instead, the 'erratics' look more like residual clumps of the overlying layer to me, well into the process of dissolution.

I hope we will find unequivocal glacial landforms in HiRise images, but I don't think we're there quite yet. Having said that, I'd be delighted to be proved wrong - my desire for proven Martian glaciation makes my standards of proof perhaps too high!

Bob Shaw

Proof is a high standard indeed!

Perhaps we should send a rover and do a spectrographic analysis on a few target boulders to see if they are true erratics. The new image that I pointed out does contain other features suggestive of both eskers and moraines. The JP2 file is too large for me to use until I fix the compatability problem with my computer. So I cannot, yet, crop the image and directly point out the feature that I refer to. Hopeful I'll get the problem solved soon. I really would like a much closer look than I currently can.