Phoenix - spring images, HiRISE views of Phoenix after the long, long winter Options

[Phil Stooke]

Doug just said in another thread that he was looking for Phoenix in the new images and couldn't find it. Well, I love a challenge. So here it is:

Close-up:

(REMOVED - SEE LATER POST)

Context:

(REMOVED - SEE LATER POST)

Note that map-projected HiRISE images at this latitude are in polar stereographic projection, not a cylindrical projection. North is at the left.

You might not believe this, but by blinking layers like Clyde Tombaugh I think I can match numerous points, not just the hardware.

EDIT: I was a bit off. Correct locations are shown below.

Phil

[fredk]

Curious story from Sky and Telescope. First the writer states:

The view here gives the impression of frosty patches atop ice-free ground, but that's an artifact of contrast enhancement. In fact, the entire scene is covered with frozen carbon dioxide.

What makes him say that? Why would there be such well-defined brighter patches if the ground was completely covered? The brighter patches don't look like south-facing slopes illuminated by the low Sun - there aren't the corresponding darker areas that you'd expect for the north facing slopes. Besides, I read that the Sun was only at one degree elevation for these images. As we know, the direct, directional illumination from the Sun would be severely attenuated by atmospheric dust when the Sun is that low. Most of the illumination would be diffuse illumination from the sky, which shouldn't produce much contrast on slopes.

Could the CO2 be continuous, but dust is covering much of the CO2, with the bright areas free of dust?

The writer also states:

We'll probably never know how just how much CO2 snow accumulated atop the lander by September, when the coating was likely thickest

That surprized me a bit, since spring equinox was October 26th, and with Phoenix only a few degrees north of the arctic circle, it should've been getting quite a lot of sunlight by September. But still I could believe that the July and August images show essentially the maximum amount of CO2 coverage. So maybe that's what he bases his claim on that the coverage is complete in the images?

[centsworth_II]

....Most of the illumination would be diffuse illumination from the sky, which shouldn't produce much contrast on slopes.

Could the CO2 be continuous, but dust is covering much of the CO2, with the bright areas free of dust?...

It looks to me like the distinctive surface polygons are present in the dark areas but not visible in the bright areas. If the dark areas were a layer of CO2 covered by a layer of dust, they should be as smooth and featureless as the bright areas.

My question is, are the bright areas flat patches of frost or thicker drifts. If the light is entirely diffused, it may be impossible to tell anything by looking for shadows around the lander.