Definitely, Stu!

However, I sure wouldn't mind if we came down within a few meters of one of these. Shooting from the hip, here, those look one hell of a lot like fresh fractures that have permitted sublimation & recrystallization of H2O...perhaps evidence of VERY extensive subsurface ice?

Quit showing those interesting features! You'll get the "Phoenix should have wheels" people started up all over again!

As far as "Phoenix has wings" occurs, I don't mind too much !

This is one of my favourite crops so far, and I think it shows that Doug's winning entry in Rui's art competition is probably very prescient... A few rocks, here and there, some vertical relief, here and there... maybe some low ridges, shallow trenches...



Can't help thinking the HiRISE team is cheating and actually photographing rhino hide with a close-up lens...

I can't avoid to think, looking at that image, that this is a tricky ground...tricky tricky...

What's so tricky about it? Doesn't look like anything Phoenix wouldn't handle to me. It's definitely going to wind up with some small tilt when it lands, with some luck it just might be tilted towards the south.

Yep, I agree... I'd much rather our bird touches down here than in one of those Death Star trenches...!

Isn't there a scale law somewhere that says a surface that looks smooth at one scale will be rough at the next scale down? It looks very smooth on scales of tens of metres, but a successful landing needs (some value of) smoothness at a scale of 0-9m.

Lawks! now I'm worrying myself

What I'd really love to see would be Doug's simulations of post-landing HiRISE images reprojected on these images... I can't quite visualise the scale of the vehicle in these landscapes.

Yep! it's what I was to ask too! Stu, can you add a scale bar?
I would say that Doug entry in the competition will be close but I think the terrain will be a little bit not thta flat. Only 47 hours to go!

Yeah...reluctantly, I have to agree. Assuming that this is a max resolution image, it sure looks like we have numerous 'rilles' of at least 0.5m in elevation (or depression!) spaced rather closely together. Gordan mentioned earlier that we might think about getting ready for some slanted landscape views...think he's right.

She's gonna make it, though, and in fact make it look easy after the fact. GO PHOENIX!!!!

What is the resolution of these images?

Resolution: the usual 1:1 on IAS Viewer which I think corresponds to 30cm pixel...

If it's the map projected imagery, it's normally 25cm/pixel.

Doug

I've been taking a second look at the HiRISE image of the Phoenix landing, in particular the large scale light and dark patterns.

The large scale darker areas such as the area where Phoenix landed appears to be darker because of the prominent dark polygons. The large scale lighter area in contrast lack the prominent dark polygons, a second difference is the rougher appearance with more relief at scales larger than the polygons.

The difference between the light and dark areas near Phoenix is apparent in the HiRISE image of the area around Phoenix, I've included a couple of closeups the show the polygons in the dark areas.


Looking at an area somewhat farther north in the same HiRISE image the dark areas look somewhat like ponds in the image, appearing to fill a low lying area.


Obviously a pond of water cannot form on the surface of Mars. Water is not stable at at the low atmospheric pressure and would vaporize quite quickly.

Perhaps instead the dark areas may be areas where a water table exists temporarily below the surface. The polygonal patterns imply that a freeze thaw cycle occurs in the area. When the ice melts below the surface water may travel from the higher rough terrain down into lower areas forming pools just below the surface.

This could explain the correlation between the dark polygons and the areas with the lowest relief and would imply that Phoenix landed over an area where water may collect below the surface or at least may have collected below the surface at some time in the past however long ago that may have been.

I was thinking that "THE" HiRISE landing site image was PSP_0022490_2485 and the location was +68.2, 234.3 deg. I've been trying to match to the orbital views with Phil Stooke's Polar Pans but have had -zip- success. The landscape has a truly fractal appearance and I've not seen many landmarks. Did I take a preliminary locations as gospel?

Anyway, I don't think we're seeing frozen ponds of water, nor a frozen shallow groundwater table. Remember, Mars has significant polar drift, and what is now polar was once equatorial a brief few hundred million years ago. Relative recent surface conditions do not allow for standing bodies of water, and whatever liquid could form quickly evaporated. I believe that the source of the ice we are finding will be hoarfrost with interbedded regolith.

I may be completely off base here, but we'll see what the chemistry of the site is and what further digging shows.

--Bill