OH NO!

An image of the area I am writing my last post about appears, while I am writing it. At least, on a quick look, I got the mountains bit right. The dark area to left is also clearly a very steep almost vertical cliff. There are bright narrow ledges and there are a couple of impact craters, sort of bent in half as the cliff angle casts a shadow across them. Plenty of sublimation features on this cliff face too. Familiar to those who follow the 67P images. There appears to be one of those round cushion, features we see at Imhotep on 67P, which a recent paper explains is likely the result of a pressurised bubble of gas below the surface or the remains of a gas conduit formed by escaping gas from below. More info: http://blogs.esa.int/rosetta/2015/07/20/inside-imhotep-2/.

There is so much to get my head around in this image, just as I thought there would be. I might be away some time.

It fits in the inside corner of the "L"

I agree - also the dark old terrain "island" (green arrow), bordered by a upwelling looking white area (green arrow).

I was thinking before that it was solely erosional processes - but the lack of a steep elevation change at the border and the few infilled border craters looks like a mix up upwelling and depositional processes as well at some point in the past in this border region. Lots to chew on here!

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If analogies mean anything, this image speaks bundles to me (caused by the most notable impactor of the Chelyabinsk meteor):

(from http://voices.nationalgeographic.com/2013/...d-globe-twice/)

The scale is a couple of orders of magnitude off, though. Not sure how well any of our analogies from previous missions/experience would work out in the Kuiper Belt.

To me it looks like the mountain chain having been exposed after erosion by the retreating ice. The question remains what is causing the ice to retreat whether its a seasonal effect or whether it is an effect of internal heat.

Anyone know how thick a layer Pluto's atmosphere would form if it froze out?

A rough fit of how the two recent images + the first "icy plains" image fit together:

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I feel like Sherlock with a magnifying glass, examining detail and putting the larger picture together.

Here is a link with information on Ted Stryk http://www.planetary.org/connect/our-exper.../ted-stryk.html

Fernando

The dark equatorial band just looks awesomely disrupted in this area. I like MarsInMyLifetime's take. The mountains have the appearance of shattered, tilted blocks of icy crust, and the aprons at their margins a bit like the chaotic matrix rubble on Europa. The dark material collecting in the troughs of the icy plains in Tombaugh could be remnants of the old surface, and the whole mess to the south has the appearance of having poured out in lobes, pushing blocks ahead of it.

These new mountains seem to have the same terrain on top as the dark area to the left, somewhat like tepuis on Earth or landslide steps seen on Mars. I agree, all analogies are off out on this new frontier. In evolution, we might be speaking of homologies (wings on bats and birds) rather than analogies. Still, weirdly familiar...

Fernando, do you ignore that Ted is a moderator on UNMSF ?

Just in case it wasn't clear, the post you were referring to was a joke; Ted is member number 33 on this forum and one of your moderators!

There is a new image of Pluto published on the New Horizons page (and Charon's image as well].
It's the same as one which was published on the NASA's page but it has clearly higher quality.
Here is mosaic of two published images.

When I started working on this, nobody had posted one yet.
Click to view attachment

...and the bottom-left LORRI image wasn't in soc yet. >_<

Edit: Replaced the image with one that incorporates details from the version deposited in the LORRI "raw" image archive.

Here is a part of an 18000 x 9000 pixel map of Pluto with the two recent ~0.4 km/pixel images added. There are some errors in the feature positions since there is a very big difference in resolution between the new images and the best global image (the difference is by a factor of ~10) and this makes it difficult to match features very accurately.

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There are some features around the mountains that vaguely remind me of Europa's chaos but since these two bodies are otherwise very different this superficial resemblance may not mean anything - it will be interesting to see even higher-res images. Exploitcorporations mentioned this resemblance too in an earlier post.


Having looked closely at the images to match features when making the map above I didn't see anything that is clearly a vertical cliff - in many areas, higher resolution or even stereo imaging is needed to get true elevation differences. The high albedo contrast can also make it difficult to distinguish between topography/shadows and albedo variations (there are some examples of this in images of Ganymede too, e.g. the G1 images of grooved terrain). Care must be taken not to overinterpret what's still a very limited dataset.

They seem to have closed off access to the metadata files

I don't think I've seen Charon jpegged to death quite so badly as what they just dropped in the LORRI archive.
http://pluto.jhuapl.edu/soc/Pluto-Encounte...osure=60%20msec

Here's a level-adjusted version.
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Arrghh! But what's probably most important, at least the image time down to an accuracy of 1 second is posted on the raw images page and this makes it possible to calculate lots of fun stuff (e.g. the subspacecraft lat/lon) when one has accurate trajectory information.

If you take the URL of an image,
http://pluto.jhuapl.edu/soc/Pluto-Encounte...0x632_sci_3.jpg
change, "level2" to "level1", change "jpeg" to "info", change "sci" to "eng", and change "jpg" to "txt", you'll get a metadata file.
http://pluto.jhuapl.edu/soc/Pluto-Encounte...0x632_eng_3.txt

Incidentally, most of the data on the LORRI image pages is just provided by the URL.
http://pluto.jhuapl.edu/soc/Pluto-Encounte...posure=Indecent
I actually took advantage of that two posts up from here, to include the description (found in the metadata file) of that Charon image that was missing from the image page.

On a related note, I find it disappointing that they recently went out of their way to remove access to browsing the directory structure, just in time for the flyby data to start coming down. I hate to see that kind of thing while at the same time they're saying the only reason they've moved away from the old 24-hour release cycle is because the data is more complicated and fragmented now.

Sublimation/deposition of N2 and/or CH4 could easily fill and then evacuate these types of features. Based on the images released today, it really reminds me of HIRISE pictures of CO2 frost subliming from martian dunes and craters. It looks like maybe that darker material (which maybe is older terrain and hence heavily cratered?) might get seasonally covered with N2 ice and then exposed during the warmer "months"?

That's good. The information that's posted on the raw images pages doesn't have range or resolution information that's detailed enough to use for image scaling, and I don't have Bjorn's skill at converting UTC times to range info with SPICE data!


It's pretty clear that they've made the raw image release process a manual one, in order to release only those images that have been the subject of captioned image releases, or which are redundant with other releases.

Each of the 10 mountains in the lower third of this new image, protruding from the Tombaugh Regio flats, has a dark crevasse/crater on or near its peak. Are they all old water volcanos?

compare:
http://pluto.jhuapl.edu/Multimedia/Science...ntain-range.png

to here, red circles:

Answering my own question, if Pluto's atmospheric pressure is 3 microbars and it froze out evenly onto the surface it would leave a layer of solid nitrogen about half a mm thick, (assuming I didn't mess up the math somewhere). So freeze out would leave a layer of frost affecting albedo only and would not be able to hide craters or other topography.

On the SOC raw images page they state a plan to post raw images every Friday that were received by Tuesday of that week. We'll see if they get into that rhythm.

The main problem with this image is bit depth, ie number of shades of grey, rather than jpegging. Presumably this means the image has been tremendously stretched from the original. It's not clear why, but perhaps it's simply that the exposure was low for the lighting.

Great new images, as always. They seem to show *yet another* new type of terrain - parts of the light, smooth area (CO ice?) appear to be interspersed with rounded, darker smooth features with varying albedos. I got fixated on one of these areas which intersects a mountain slope. Am I crazy, or does this darker stuff look like transparent ice? The mountain seems to show a sharp elevation line where it meets the darker material surrounding it, and yet darker streaks on the slope are visible past that line.

I cut out the area which seems to show this effect most prominently and enhanced its contrast, and it seems to almost disappear. Is this even possible? I assume, if so, that the transparent material would likely be the youngest? Albedo variations in the other areas could be explained by bubbles trapped in the ice and/or variations in surface cover.

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That was my initial impression when I saw the release today, so if you're crazy then so am I.
_{Then again, I also like to pretend the little darkish specks everywhere in that area are trees, so, yeah, we might be crazy.}

If I let my imagination go with that I see large ice covered sea that expanded and burst through its icy crust. The polygonal terrain is the from convection in the sea preserved as its surface flash froze, the new mountain range in the latest image is remnants of the old crust pushed up against the shoreline, and the light terrain beyond that and bordering the dark cratered terrain is an old surface that was flooded filling in its craters.

My imagined shoreline:

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One thing that really sicks out for me is the sharp transition from cratered dark terrain to mostly uncratered light terrain. Covering craters in the light terrain must what, 100s of meters, kilometers of material? I haven't seen any claims that that much ice in being moved seasonally. Perhaps over millions of years as the precession of Neptune's orbit changes the latitudes most likely for Pluto's icecaps to form.

Well, I must be crazy too!

I'm particularly curious about the darker polygonal features located at the feet of the new mountain ranges. It looks like those polygonal features are undergoing some kind fo transformation there in association with the mountains. Well, they looks like thawing "icy ponds". What could make that white ice turn darker? Could it be the darker polygonal features are active while the ones on Sputnik planum are more stable?

To be noted, it seems a lot of darker "bubbles" are concentrated along thoughs near the mountain range. Whatever the reasons, it seems activity is quite intense around mountains.

@Alan: it seems the mountains are akind to islands...

Another question: I've been intrigued by the circular "impact" in Tombaugh Regio. IIRC, NH team during a press conference said the heart was the place were the concentration of certain ices was higher. Could be that this ice was brought by the impactor? Ice from the crust exposed by the impactor? Or, just like the other craters, bright material likes to gather in the lowest altitude?

Matt

Main reason that light stuff turns dark (esp. on icy worlds) is that simple organics exposed to UV combine into an array of more complex molecules (thiolins.)

Origin of the unusual ices? Good question; too early to tell. Hopefully as more data is sent down the planetary science community will have some ideas.

I would not expect an impactor to be so overwhelmingly enriched in CO that it would produce a substantial deposit in a such a localized area, though. The impact energy would blow stuff aaall over the place (most of it moving at or beyond Pluto escape velocity, actually. Low-speed impacts in such an empty area of the Solar System seem vanishingly unlikely.)

The two high-res frames have some overlap. Here's the average of the two frames over most of the overlap region:
Click to view attachment
This reduces jpeg artifacts/noise, but the effect is subtle (perhaps sqrt(2) improvement in S/N).

An attempt to summarize what we've seen of this southern portion of the Tombaugh-Cthulhu boundary as of today's release, rendered in spectacular fudge-o-vision. Riddled with position errors, but a passable "artistic" overview for the moment.

Click to view attachment

Wouldn't have imagined in a million years that I'd type the phrase "Tombaugh-Cthulhu boundary".

Whoa.

Some of the spookier names are becoming more apropos with each release. This place is quite alien in appearance indeed.

I only see eroded matter that corresponds to what is on the mountainside, i.e. a dark streak on the mountainside has created a corresponding dark streak on the flat plain below, and none of the features are transparent.

We'll definitely know when we get to see stereo images of the region.

You've got it in the right ballpark - if I did my math right that's it. =)
In one earlier post I compared it to the ice we scrape of a car window in the morning. Meaning something between ½ mm to 1 mm thickness.

It's a shame we don't have any albedo data from the 1860's to compare. While I'm ignorant to the crystal lattice structure of the N2 frost in the Plutonian surface environment, if it affects light in a similar fashion to a windscreen hoar-frost then the albedo change would be pronounced. Tholins on the surface may preferentially sequester frost build-up to certain locations over others on the sunward hemisphere but what of the hemisphere that rotates out of darkness as Pluto recedes; the lengthy year affects the cold-traps on the surface in what ways?

I dunno how much significant variation there would be in terms of solar radiation, though. The peak here at perihelion is still less than a watt/m^2, so the max variation is obviously less than 1 W.

Maybe there are some cryogenic substances that would be sensitive enough to do state changes based on that small variation, but it seems unlikely.

Fair enough nprev. Given that small variation it seems that the atmosphere wouldn't be in any danger of collapsing after all? If the atmosphere is spared that fate, then would the insolation variations still be the energy source for any increased sublimation effects we're seeing, or are you saying when you mention state changes that sublimation does not occur in recent times other than as a steady process in the low pressure?

Not sure; not enough data. However, the most recent thinking is that the atmosphere does not in fact completely collapse. Given the tiny amount of solar radiation variation that's probably not very surprising in hindsight (though undoubtedly there are many other reasons behind this conclusion).

Some climate dynamics around the solar system are stable and consistent; others are chaotic, and I don't think we know enough to determine from first principles, as opposed from observation, which are which.

Some Septembers, a hurricane hits Florida. Most Septembers, one doesn't.
Some millennia, Earth is in an ice age. Others, it isn't.
Jupiter's southern hemisphere has a huge, enduring anticyclone. Its northern hemisphere doesn't.
Some perihelia, Mars has a massive global dust storm. Some, it doesn't.

If these things vary from one instance to another, it seems like predicting Pluto's aphelion "weather" is apt to be speculative until we see at least one of them happen. (Which will be a different "we" than anyone alive today.) Maybe they aren't even all the same. I don't see how we could predict it, given the unknowns.

I think it's important not to overthink these "if the whole atmosphere precipitated out..." scenarios. Pluto's "whole atmosphere" is highly transient, 140kg is ripped away every second. We don't know wherefrom within / on Pluto it's coming from, but it's clearly replenishing itself. Hence any snows/frosts are unbounded by the current or peak masses of gases in the atmosphere.

Likewise, I think one should expect that the CO in the area where it is would (probably) be replenishing itself too. CO sublimes, and it's even more likely than N2 to be lost to space. So it too has to be coming from somewhere. And the obvious answer would be, "the only place on Pluto where we see it".

The contents of the atmosphere at any given time might not be able to bury significant topography - but vast amounts of volatiles sublimating from terrain in summer and depositing on terrain in the polar night, might.

I've been thinking more about the nitrogen loss issue and it leads in some interesting directions.

Reasoning:

1) If Pluto is losing 140 kilograms of nitrogen per second from an already tenuous atmosphere then it has to be constantly replenishing it.

2) It could A) have been always replenishing it, or B) we could just by chance happen to observe Pluto at a rare time when something new is causing it to emit an atmosphere that's eroding.
B seems unlikely, so let's follow through with (A).

3) The nitrogen could be some combination of A) on the surface, and/or B) moving up to the surface.
There appears to be nowhere even in the ballpark of enough nitrogen on the surface to sustain (A) - a kilometers-thick layer. So either we're catching Pluto at a rare phase where its surface nitrogen is almost depleted, or the process is overwhelmingly due to (B).
(B) sounds more likely.

4) If nitrogen is moving up to the surface, it is either (A) being transported as a solid tectonics, or (B), flowing as a fluid (liquid, gas) through ground pore space, fractures, etc
While we can't rule out (A), tectonics on a body like Pluto would certainly be unexpected by conventional means** (note later). So let's go with (B) for now.

5) Nitrogen can flow as (A) a gas, requiring higher temperatures and lower pressures; or B) a liquid, requiring lower temperatures and higher pressures.
Given that the quantity of nitrogen loss implies significant depth, and Pluto should have little internal heat, (B) seems more likely.

Caveat: Nitrogen's ability to reach a liquid requires either A) a temperature of at least 63K (somewhat more at higher pressures), or B) a eutectic with other compounds that results in a lower freezing / boiling point. Neither of these are particularly onerous requirements but must be mentioned. Note, however, that some way or another, nitrogen must be reaching the surface.

Presumed consequences of all of this:

1) Liquid nitrogen reaching the surface of Pluto will freeze due to insufficient pressure, creating a permafrost. It could be permafrost bedrock or permafrost sand/rocks (predominantly of water ice). Exception: If pressure / flow rate was high enough, it could flow as a sort of nitrogen cryolava, spreading via pillow formations and the like.
2) The permafrost depth will vary depending on Pluto's orbital cycle, creating frost heaving effects. The quite deep permafrost depth combined with Pluto's low gravity could allow these to build up to impressive scales.
3) Large celestial bodies are rarely uniform and aquifers of any kind rarely equally distributed or with equal flow rates. Hence we would expect an uneven distribution of outflow.
4) Areas with low outflow rates would evolve slowly, or potentially not at all if sublimation strongly dominates inflow.
5) Areas with high outflow rates would evolve rapidly.
6) One would expect, like on Earth (pingos, patterned terrain, etc) that repeated freeze-thaw effects to build up areas of higher concentrated ices (up to the point of being nearly pure) while pushing ground debris steadily aside.
7) Within the caveat listed earler, nitrogen under sufficient depth (and thus pressure) will not freeze; it will remain liquid. Hence if enough of a nitrogen builds up in an area (whether pure or dispersed in a sand/gravel matrix), it would evolve into an ice cap over subglacial lakes / seas in that location. The ice cap would need to be 1-2 dozen meters thick - more if the liquid is a eutectic with, say, neon, or if the surface requires significant thermal insulation to reach the melting point.
8) The loss of this vast amount of aquifer nitrogen over geological time periods would cause dramatic subsidence in the crust. This would result in significant tectonic effects, such as mountain and horst/graben formation.
**9) Given Reasoning/#4, this in turn could also bring up more nitrogen to the surface.

Thoughts? Has my logic strayed anywhere?

From time to time, some of us have something to report about the naming of features.
I must say that I’m really delighted NH team named first Pluto discovered Mountains after the late Tenzing Norgay. Tenzing climbed together with Edmund Hillary on May 29th, 1953 and sat up foot on the Top of the World right after him.
So, Tenzing Norgay is the Buzz Aldrin of the Everest.

As UNMSF’s Old Timers may know, I was a member of the Everest 50 Expedition back in 2003 (hence Climber) that attempted the climb to celebrate the 50th anniversary of the first conquest. I missed meeting with Sir Edmund in Katmandu by a mere 15 minutes but I get to shake hand with Tashi Tenzing Norgay up in the Mountain (see the picture I took then).
Tashi is the grandson of Tenzing Norgay and, like his grandfather and father also climbed the Everest.
I’m sure Tashi is even prouder of his grandfather now that he has been inspiring NH team.
The History is sometimes weird. It says that the first two men on the Everest were Hillary and Tenzing but they were actually Hillary and Norgay.
Let see if this news is going to make a … Buzz

Not bad. Although your comments are directed toward a Plutonian atmosphere, the driving force behind this is Pluto's hydrologic system (and perhaps cycle) based on Nitrogen (et al) under cryogenic conditions.

One puzzlement for me is that Pluto has a surface gravity and temperature of perhaps 1/2 that of Titan, so why does it have a so much lower atmospheric pressure (0.0065 kPa vs 147 kPa) than Titan? Is the rate of N2 replenishment from the interior less? Is the Dark Pole that efficient a cold trap? Or does Titan have an anomalously thick atmosphere for other reasons?

These are indeed wonderfully strange little worlds.

--Bill

Thank you for the head's up. I had never fully read the list of administrators and moderators. If it was a failure, it has now been corrected.
I also failed to detect the joke and my sole intention was to make a positive contribution.
Hopefully I hurt no one other than myself.
Fernando

Looking at the new image release caused me to think back into the ancient past, OK, it was only two weeks ago, when I was thinking about the whale. The whale-area being dark should be absorbing more sunlight than the bright areas. This implies that ice should melt first here. It's also at the equator where ice should melt first.

So, my theory was the the dark material is actually the oldest surface on Pluto and the brighter material is ice that covers-up the dark material. Basically Pluto is the dark material where as everything else is a surface layer.

This surface layer of ice is transported by something during the northern summer where Pluto is far away the Sun and southern summer where Pluto is far far far away from the Sun. This leads to a continued resurfacing of the top layers of Pluto by season as the dark material is covered (snowed on, possibly, cryovolcanic plume debris, maybe). Then as the ice moves to another part of Pluto, melting occurs and the older dark terrain is uncovered again.

The problem a few weeks ago was that the dark material appeared to have no craters. Now in the newest released image, there are craters in the dark terrain. And, many craters in some areas.

So, maybe the idea has some merit after all. If this is correct, where you see dark material, you are seeing under the ice to the older terrain. This also means that the whale is a temporary structure. It could be a bear by Pluto's next orbit.

Andy

Being a bit pedantic here but the "half a ton per second" that keeps being mentioned isn't quite right. The original statement by Fran Bagenal was 500 tons per hour, which works out to 0.14 tons/sec or 3e27 N2 molecules/sec, in excellent agreement with recent models (Tucker et al. 2015, Icarus 246, 291; Zhu et al. 2014, Icarus 228, 301). FWIW this also happens to be roughly the same outgassing rate as for comets near 1 AU, although in that case it's mostly H2O, CO2, and CO.