That stuff extruding out between the cracks reminds me of N2 phase change videos, with it expanding as it freezes: https://www.youtube.com/watch?v=FReIs6rQbPM

My guess is you are on the right track here. These look a lot like the expression of active convection (raised centers compared to the rims). The same origin has been proposed for the formation of canteloupe terrain on Triton (in which the individual cells have low centers and raised rims...a product of the convection cells shutting down and cooling conductively sometime in the past).

If these are truly active (Rayleigh Benard) convection cells, then the characteristic size scale (~40ish km) provides a way to estimate the depth of the convecting layer: ~1/3 the characteristic width.

I am now a bit more confident of this speculative mechanism I suggested on the 15th at the 'port:

The water ice mountains are sharp and jagged, and do not show evidence of meteoric weathering. This means that either they were formed very recently (how??) or they were exhumed very recently from a frozen CO/N2 ice plain.

If the solids are gases such as N2 or CO which sublime from warmer locations, and re-freeze into cooler locations as Pluto goes around its orbit, and these frozen gases exist in huge amounts (such as the bright plateau shaped like the Pluto dog head may be the remnant of a giant glacier of these frozen gases) - then perhaps there is a xx year cycle (247 ?) of sublimation and infilling on a massive scale, which is reshaping the object's surface in dramatic fashion.

~ ~ ~

A speculation of the mechanism of the Plutonian heat engine, whose energy source is ultimately solar....

If huge amounts of gases are subliming from one location on the planetary surface during the summer (for example, the equator), and re-freezing into cooler locations (for example the poles), then the mass distribution of the body will change significantly. If the gases re-freeze in a non-spherically symmetric manner, then the planetary mass distribution will be non-symmetrical, and more importantly, lead to a unbalance in the idealized mass orientation of this tidally locked binary planet. This will create torque and cause cause flexation of the crust, generating heat as Pluto attempts to re-orient its mass distribution to the gravitationally lowest energy mode. This re-orientation of the axis should which could be the engine which drives the venting.

that would require the convection cells to be liquid. I really doubt that.

I've been wondering too. It does look like there should be three LORRI images.

NASA Post Flyby News Conference on the New Horizons Mission -- July 17:
http://www.space-multimedia.nl.eu.org/inde...;catid=1:latest

Please see post #638. I really doubt the Youtube energetic N2 freezing phenomena would be operant on Pluto.

This would have significant implications for the other known Kuiper and SDO objects having activity of the levels of Pluto (speculated). Seems only Haumea with it's moon Hi'iaka might provide sufficient energy to cause the same process. Hi'iaka is big but still quite small compared to Charon relative to Pluto.

-kap

Screen capture of 3 frame mosaic

Click to view attachment

Highly viscous material can flow at sufficiently large scales (magma, glacial ice), but can be stiff or even brittle on a human scale.

alan, thank you for the new picture! Are those ice mountains being exumed by sublimation of CO/N2 in that picture?

And of streaks

Click to view attachment

Seems to me that you would need to move miles of crust from place to place to change the orientation that much. Even if you could, the Pluto-Charon orbit would still be the same shape.

Still, it's probably worth having a grad student run through the math. Physics trumps intuition any day.

Yep, those are swear-jar images, all right!

Looking forward to the high-res images, now. Going to be really, really interesting.

-the other Doug

This was the best "high-res" Voyager could do..(but of course it was great for the time - erupting geysers)

Click to view attachment

True, but extremely viscous material doesn't flow in Benard cells structures at the km scale. I doubt you could even find Benard cells in extremely viscous tars at the beaker scale. With extremely viscous materials and a glacial pace of heat flow loss, the organized heat flow at high viscosity would be tiny compared to the heat flow dissipation in competing radiative loss and local chaotic convection, and so the nice organized flow pattern which creates the hexagonal structure would be lost (signal to noise problem, essentially). Just my 2 cents.

Consistently, several troughs on Sputnik plain appear to have central structures, perhaps central ridges:

Click to view attachment Click to view attachment Click to view attachment

I'm a chemist not a geologist, so what do I know! But if you have "things" on discontinuities at a lab scale they're "growing". From the vapour phase especially. What came first - the polygon boundaries or the objects?

Agreed, this would need modeling. I was considering a putative mass of a huge glacial deposit of frozen gas, km's thick, cyclically moving via sublimation and refreezing. This wild idea seems a bit more possible after today's new data.

The Pluto - Charon orbit would remain the same, just that the attempt of axial re-adjustment to a asymmetric mass distribution would drive a heat engine.

If you had shown me these pictures before today, I would have promptly and confidently identified them as Europa.

The putative streaks make sense if the wind direction is from the north, and directly due to insolation. I was wondering if any streaks aligned with the CO localized in Tombaugh, as if the CO came from a cryovolcano and eruptions streaked the darker terrain, but it looks like nothing aligns with that direction.

True - but because the mission concept of science in the blind didn't need high real time rates - so the comm system was minimized accordingly. If it had been designed with a scan platform it would have had a bigger antenna (or if designed today maybe laser comm) to facilitate a much higher downlink. Somewhat related - I'm surprised NASA took the risk to go through the Pluto system plane in the blind - it's a violation of NASA critical event observational protocol - I would have expected at least a 5 minute turn to earth to "see" the crossing event, before resuming science. However it all turned out ok so I'm happy it was flown this way!

Speaking of scan platforms and larger antennas, I have not-so-fond memories of Voyager 2 (at Saturn) and Galileo, respectively. I'm glad they were able to work with what they have.

Just curious: What will the solar wind do to those 500 tonnes of N2 escaping Pluto every hour? Might it be that some fraction of those materials are intercepted by Charon, rain down and interact on its surface?
Fernando

There was actually a movie

http://solarviews.com/raw/nep/geyser.mov

I'm also wondering if that N2 is escaping the Pluto system gravity well completely. Could it fall back on Pluto during when the planet is further away from the sun? Thus perhaps Pluto is to some degree resurfaced on an orbital cycle?

Reduce risk? Less moving parts with fixed HGA ie NH. Galileo failure of HGA motor and non-deployment for eg - not good. NH's maneuvering with thrusters seems to have worked perfectly. Maybe saved cash too with this method. Win/win.

Is it possible they're more akin to terrestrial plate tectonics? As in: some cracks are puling material down, others are welling material up?

This was one the best images of geysers but there were more images with higher resolution after that.
Those higher resolution images show mostly plains and cantaloupe terrain. This is simply sad fact of outer Solar system flyby missions. There is no possibility of re-imaging some interesting terrains later.

This one's even more impressive, starting about a minute in:

https://www.youtube.com/watch?v=b7K-6zEhtYw

Nitrogen can be really violent during phase changes!

I'll note re: liquid flows: Pluto gets to liquid nitrogen temperatures, it just needs the pressure of a dozen or two meters of nitrogen ice over it (fluffy and/or with lighter ices to maintain buoyancy).

Anyway, I can't help but again think of ice wedging and pingos:

https://upload.wikimedia.org/wikipedia/comm...o_wedge_ice.jpg

Nothing's going to be a perfect analogue, we're dealing with very different fluids. But one way or another I strongly suspect many terrains, and in particular this one, to be driven by phase changes - including potentially ice/snow-capped liquids. And again, note the "filled cracks" with central ridges between them, like one sees on Europa - again possibly suggestive of liquids. Europa by comparison:

http://josephshoer.com/blog/wp-content/upl...uropa-crack.png

Compare:

http://www.unmannedspaceflight.com/index.p...st&p=224012

Consider the possibility that this could be an intermittent - even potentially present, if I may dare - ice capped cryosea, with the non-cellular, pitted area being where it's not deep enough to liquify at the bottom.

Is it me or do the 'hills' on the righthand side of the Plains image look like they're following the troughs? Could dark material be rising up somehow and building up there to form the dark areas? If there are ridges in the middle of the troughs as someone spotted earlier then maybe that's how the dark stuff is building up - they're being extruded from those?

It was the three-frame "motion" imagery that sold the idea because you could see the plume moving.

Andy

Won't open/play for me unfortunately. Was this product available 3 days after the flyby of Triton? I'm just trying to make the point that we are not comparing apples and apples with Voyager and NH products at 3 days post flyby. More like apples and oranges. Anyway lets enjoy all the fabulous NH images coming down the pike, I am used to the concept of delayed gratification for this mission.

I would speculate that the comm system was dimensioned based on the available mass budget (as well as power), which was in turn driven by the launch vehicle capability and desired transit time to Pluto (bounded by no-Jupiter-gravity-assist worst case scenario).


Even a 10x higher rate would still pale in comparison with the rate actual observation telemetry is generated. Laser comm is even to this day considered to be iffy for anything beyond Mars until it's a much more proven technology. Europa mission will still rely on radio comms. Furthermore, a scan platform for NH would have increased mass and cost severely. One of the design philosophies for NH was as few moving parts as possible, given that the primary mission happens almost a decade after launch.

With a scan platform, we might have ended up with a more capable spacecraft. Sitting on the ground. In the form of yet another PowerPoint presentation...

It does seem like some process is concentrating material into those troughs.

Whoa. This is a wonderfully strange little world.

My take is that these are not convection cells, but active margins of a fractured icefield. I doubt that we are seeing large-scale shading from relief, we see albedo differences around the fractures.

I've backpedaled from my earlier musing that

"I'm hoping that the light heart-shaped area on Pluto does not turn out to be a big snowfield or dunefield-- that might make for such a _b o r i n g_ primary target area."

but will suppose that if Tombaugh Regio is _this_ interesting, think of how bonkers the rocky margins will be once we get the images... :0

--Bill

The abrupt, slightly sinuous boundary between the rugged terrain and plain is quite striking. It doesn't seem to be a simple impact rim:

Click to view attachment

Exactly as Ugordan said.
New Horizons is excellently designed machine for its mission.
Similarly Voyagers were (at their time) excellent designs.
In both cases there wasn't much space for another improvements within theirs mass and power margins.

Haven't they released yet the full res version of the mosaic? IMHO it's the best image to fully understand the regional geology.

Click to view attachment

Click to view attachment

It is apples and oranges right now because it will take a while to get the full of imagery back. Once the full set of images are back (non-lossy), then it will be an oranges to oranges comparison.

The Voyager tape recorders (which really have tape) were much much less reliable and much smaller (data-wise) than the two solid state recorders on NH. The option of not sending back a good portion in real-time was not available for Voyager. Voyager's use of real-time was a necessary rather than a choice. If there was rain over the receiving site, the real-time images were lost since they weren't stored onboard. The size of each image was also much smaller with the early 1970s-era Vidicon tube used to collect the photons.

https://news.google.com/newspapers?nid=1842...04118&hl=en

Andy

Not yet, but I can't wait to see the 'messy' area in the right corner.

Jason Cook answered some back and forth questions from me and others on Twitter (initiated by Alex Parker): https://twitter.com/Alex_Parker/status/622109107252789248

This image is some type of CGI or perspective warp of the first Pluto image?

--Bill

Information on cryogenic eutectics here:

https://books.google.is/books?id=rTc8AAAAIA...tic&f=false

Remember that Pluto's surface temperature (ignoring any potential for internal heating, localized variations in surface albedo, etc) is said to be 35-55°K.

Nitrogen-oxygen has a 50,1°K eutectic point.

Nitrogen-CO is 62,6°K (aka, that of pure nitrogen).

Pure neon has a triple point of 24,6°K - unfortunately there's no eutetic info for it, but clearly they range down that low.

This paper covers nitrogen-methane:

http://dare.uva.nl/document/2/391

62,6°K triple point pretty much steady all the way up to around 20% methane.

https://books.google.is/books?id=VC2mKJlHbo...%22&f=false

Carbon monoxide-methane eutectic has a eutectic temperature 51°K.

I found no data about more complex mixes than that. Obviously neon can bring it way down, but some binary mixtures work at normal Pluto temperatures without neon.

Obviously if the temperature goes up to say 65C, pretty much everything that's mostly nitrogen leads to melt given a couple dozen meters of snow/ice cover.

It's interesting that the area to the south of Sputnik Planum (to the right of Nergay Montes) looks so smooth. I don't know if that's due to image compression (seems unlikely though) or whether there really aren't any ridges or troughs there. It just looks like a huge featureless snowfield or something. Looks almost like the smeary dark streaks in it similar to the are the dark edges of some of the polygonal features to the north that have been covered up by material there?

The pitted surface area in the close-up they have shown has a similar appearance the area south of Sputnik Planum in the 3 frame mosaic, perhaps indicating that the petted surface is much more extensive. The shape of this area extending away from Sputnik Planum brings to mind a glacier. The pits may be crevasses or a lag deposit that is sinking into the surface as it causes the material below it to sublimate.

MOD NOTE: This thread is for the immediate encounter phase and is time-based. It will close at some point next week as the data download from NH transitions into a steady-state routine that will last for a number of months.

As with other missions we will create threads for specific science findings & topics once there's something to talk about, as in published papers, etc. Our comments as bystanders do not qualify as such.

I also remind everyone to carefully review the Rules and Guidelines (the link to which is located in the top left section of the page under the banner) before posting, with particular attention to posting etiquette (section 2).

Sure looks like... you know... a coastline, doesn't it?

Still voting for frozen-over cryosea, with the near coasts fully frozen to the bottom and the further out areas only frozen on the top several dozen meters..

It may be the low resolution playing tricks on the lighting, but there appears to be a polygonal depression in the plain (marked with arrow):

Click to view attachment

Additionally, there may be a couple similar pits (or hills) to the south.

I'm wondering about the effects of Pluto's mass loss on the moons. On the one hand drag caused by the extended escaping atmosphere would cause spiralling in, but on the other hand a progressively less massive primary would cause spiralling out. Which is the dominant effect for various sizes of orbiting body? Are there implications for the stability and longevity of resonances within the system?