You also wouldn't expect its brightness to be so strongly correlated with the surface limb brightness.

The color version has been processed in a way that makes the cliff less obvious, but if you look carefully at the shadow beyond the cliff base I have marked in orange, you can see that the surface features that are illuminated outside the shadow continue into the shadow. The shadow is real.
I can't be exactly sure how high the cliff is or therefore how thick the beached slab is. Even if there has been significant slumping of the cliff, the slab has still got to be at least 4 km high. That is pretty amazing.

The map released was a methane map. It shows where the methane is, it doesn't say that any of it is all methane. Any methane could also just be a thin surface layer.



I'd advice you to use Machi's tables, they contain all/most LORRI and MVIC imaging sequences around the time of closest approach. Emily also has an overview of the LORRI imaging sequences in an image here.

The highest-resolution images released yesterday are almost certainly from the M_PAN_1 sequence (which is indeed the sequence with ~ 120 m/pixel resolution), or a sequence directly before it that we don't have the name of.

What you have labelled the 70 m/pixel track corresponds to the P_MVIC_LORRI_CA sequence, which should be the highest-resolution imaging sequence of Pluto we'll get (it faces some competition from the P_HIPHASE_HIRES sequence, which are the LORRI images taken around the same time as last week's MVIC sunset panorama).

(the global MVIC image from yesterday would appear to be P_Color_2 at ~ 650 m/pixel, per what John Spencer wrote about per-pixel resolution being multiplied by 2 for release captions)

There is no detailed information on exactly how the color version was processed. Secondly, even in the grayscale version there is nothing that is obviously a cliff. Pluto has very large albedo variations and you need stereo imagery to get accurate topographic information, including information on whether there's a cliff there. As lars_j said, you are probably vastly overestimating things. This is still a limited data set that's easy to overinterpret.

This forum might break when the 70m/pix set comes out.

I certainly wouldn't rule it out out optical scattering.

There does appear to be some delicate structure to the bloom however.



Maybe it is one part optical scattering, one part haze layers.

--Edited for clarity.

I just ordered myself a 40"x40" poster print of the full disc image. Couldn't resist. Using my upcoming birthday as an excuse.

Agreed, so I think this is probably mostly optical scattering. However, I was surprized at how bright the atmosphere was in last week's crescent image relative to the sunlit surface. Of course this new image is from a completely different phase angle, so maybe some of the atmospheric guys could chime in as to how likely the phase function would imply observable atmosphere in the full disk shot.

Anyway, we can pretty clearly see a portion of the disk beyond the terminator lit by scattered light in the new image:

The upper portion (top three arrows in my pic) appears quite strongly blue, which might suggest that the atmospheric scattering is blue. However, we'd need to see the original data to be sure. It might simply be that the response of the blue channel is greater than the other channels at low illumination levels, or that the correct relative channel weights haven't been maintained at low illumination levels in making the composite.

It could be that the NIR channel was set to the green channel. That would be the most likely to capture the faint light at the terminator no? It just seemed strange that there wasn't any apparent red signatures in the bloom if it is simply optical scattering unless, as mentioned, the blue channel is more sensitive.

I noticed that same "noontime haze" when I tweaked that new image from NH. Turning the Tweakometer knob up higher there are other "layers" of detail much higher. I'll assume that this _may be_ an artifact of the preprocessing done by NH before posting.

FWIW.

--Bill

The terrain looks like the west coast of {Iceland} Greenland, viewed from 15 miles up.

Edit - sorry, wrong island...

The snake skin and arcuate depressions (some marked in red) seem to coincide with the eastern lobe of Tombaugh Regio (and Tartarus Dorsa):



Do the arcs 'transition' into the pits to the north, or are they completely different in nature?

Edit: These features may very well extend around much of Pluto's equator. They are absent from Sputnik and areas to the west possibly because other materials (plastic nitrogen, tholin mantle, etc.) preclude their formation.

Since the steep faces of the arcuate depressions all face south, their orientation could be due to Pluto's asymmetrical seasons. Working out the thermodynamics of the yearly cycle is a bit above my pay grade, though.

The strongly-defined striations of the snake skin could reflect some aspects of the ice fabric. Perhaps some other process (e.g. tectonic movement) could enhance its formation.

"Rich" is, of course, a relative term - I don't think anyone's saying that these aren't overwhelmingly nitrogen ice. Nor do I think anyone expected any of the ices to be devoid in other materials. We already know that Sputnik is, for example, also rich in carbon monoxide which, like nitrogen and unlike methane, is dense both as a liquid and solid. Bur as for bulk materials, I haven't seen anything from the team suggested that, as for the bulk, that it's predominantly anything but nitrogen.

If it were in any large part methane, Pluto's atmosphere would be too. Methane sublimes easier than nitrogen.

I'm not sure what you mean. I assume you mean Vestfirðir (northwest), but it doesn't resemble that at all to me. The glacial-cut valleys don't at all run parallel, they run downslope.

To me it looks like giant-scale pahoehoe. Though I would be shocked if the cause was anything even remotely resembling that. If I had to guess, I'd guess that it's the same cause that's believed to cause comets to develop "necks" - ridges = shadows = more pronounced temperature differences over the course of a day = greater cracking = greater sublimation.

But I wouldn't put too much confidence in that hypothesis either...

This is how I imagine the "snakeskin" or "dragonscale" terrain looking from ground level. But I'm probably way off.