[X] My Assistant

[Stu]

Sorry Admins if this isn't exactly the right place to put this topic, but I struggled to find a better place... feel free to move it if appropriate.

As Phoenix's landing approaches I've been doing a lot of picture research to prepare my talks, and have really had my eyes opened to how beautiful and dramatic Mars' polar caps and polar regions are. I guess I've neglected them before, concentrated too much on the more glamourous and better-known landing sites of Viking, Sojourner and the MERs, but wow, there's some amazing sights up there in't far north...

So I just thought I'd invite the imagesmiths out there to put up their best/fave views of the poles for everyone to enjoy, as part of the build-up to the Big Day. Here are the images I've made for my talk - not directly related to the Phoenix landing site, I know, just "wow!" images...

This is a crop of an MGS pic, showing part of the Chasma Boreale...



... and this is a crop of a hiRISE image showing a neighbouring area...



Ok, come on, share what you've got... or if you've got nothing, make something...

[n1ckdrake]

North Polar Scarp and Layers (PSP_001341_2650)

[n1ckdrake]

South Polar Layered Deposits and Residual Ice Cap (PSP_006270_0955)

[ugordan]

South Polar Layered Deposits and Residual Ice Cap (PSP_006270_0955)

An awesome sight, I only just saw it yesterday for the first time. That's some weird terrain there...

[nprev]

Yeah. Much of the south polar area terrain is almost hallucinogenic; arguably the oddest landforms we've seen on any world except Earth, which still holds the title of "Weirdest World in the Solar System" (to say nothing of its inhabitants... )

[peter59]

I prefer black-and-white photography.


Fragment of South Pole Residual Cap Swiss-Cheese Terrain (PSP_005095_0935)

[n1ckdrake]

Northern Polar Dune Field

[n1ckdrake]

South Polar Geysers (PSP_003285_0935)

[belleraphon1]

I have always felt that not enough attention has been given to Mars prime volatile, CO2! Amazing geology and totally un-Earthlike.

Craig

[nprev]

...that geyser shot is amazing, Nick! I wasn't sure if I believed in those things or not; think I do now!

Notice that the source of the rightmost one in the shot is surrounded by what look like outflow channels, but of course they can't be since CO2 sublimates. Are these surface collapse fractures from depletion of the buried CO2?

[marsbug]

To my untutored eye it looks like the channels converge on the midpoint of the largest diagonal crack (highest on the left lowest on the right), which has a depression at its center. Could this be the original vent, and a new one has sprung up at a later date due to the weakened crust in that area? And why does the fan extending from the vent appear dark? whenever I've seen solid co2 its been white.

[nprev]

I've been thinking that it's either blowing out mixed-in dust or--just maybe--organics. Would like to see some spectrometry done on the effluent fans.

[belleraphon1]

All...

from the current HRISE SIM webpage
http://hirise.lpl.arizona.edu/sim/

"Starting last January, HiRISE embarked on a campaign to monitor the seasonal sublimation of the carbon dioxide ice in a few regions in what is known as the “cryptic terrain,” close to the south pole. The goal of the campaign was to use the new capabilities MRO / HiRISE has to offer (high resolution, color, the ability to collect stereo pairs and make anaglyphs) with CRISM to study a process unlike anything we experience on planet Earth"

go here to download a presentation given at the AGU by C. J. Hansen and A. McEwen.

http://hirise.lpl.arizona.edu/pdf/agu_press_conf_dec07.pdf 3mb

A quote fron the presentation

"Surface morphology is so un-earthly that a new taxonomy is required to describe the features we see".

Craig

[n1ckdrake]

Are these surface collapse fractures from depletion of the buried CO2?

Yes, I believe these spider patterns are formed during eruption caused by rapid pressure growth under the CO2 ice plate.

And why does the fan extending from the vent appear dark? whenever I've seen solid co2 its been white.

From what I currently know, when the CO2 jets exhaust into the atmosphere, they carry along dark sand like material that formed as a thin layer on top of the CO2 before the CO2 sublimated.

[n1ckdrake]

South Polar "spiders" (PSP_003113_0940)

[n1ckdrake]

Bright Streaks and Dark Fans (PSP_003113_0940)

[marsbug]

Beautifull!

[n1ckdrake]

Basal Unit and Dunes (PSP_001712_2635)

[scalbers]

Here's the big picture of the permanent north polar ice from Viking (PIA00161).



It might be interesting to zoom into some of the other images presented here using the above image as a context (e.g. the ones in the next post). I like the flyover in the first link from bellapheron1's post #13, though it would be nice to have some further intermediate resolution imagery added.

[scalbers]

Mars Express North Polar Perspective View. Unsure of vertical exaggeration factor:



This image is a closeup of the upper right in the above one...



More at this URL:

http://berlinadmin.dlr.de/Missions/express....2005_eng.shtml

[djellison]

Frustratingly, the available DEM's for those observations do not extend as far as those features - they've elected to cut them short of there.

Doug

[scalbers]

Yes, would be nice to have DEMs available to make zooms. Meanwhile, here's a nice zoom from a previous UMSF topic:

http://www.unmannedspaceflight.com/index.php?showtopic=2711

And here is a THEMIS feature page on Polar Caps / Ice

http://themis.la.asu.edu/theme-polar_ice