The Pluto surface resemble a Itokawa asteroid surface :-/

the scale is completely different. Itokawa would be at most a handful of pixels in the image of Pluto released yesterday

Yes yes i know, but remeber this, at small scale.

It's not often that we see scientific paradigms shattered the way New Horizons did yesterday. So much of what was thought to be known about the Pluto Charon system turns out to be wrong. What was once a distant frozen point of light has become one of the most active worlds in the Solar System. Some parts of the terrain remind me of Valles Marineris, others of Io, while much is simply Plutonian. Thank you to the New Horizons team for one of the most shocking scientific press conferences in a very long time.

I have the feeling that the geology seen in Pluto close up image is orientated as if due to a big wave caming from one direction. This is true for the "dunes"on the rigth end side as well as the Tiger stripe like feature. Anybody else agree?

Some very specy imaging work from people like John VV, Sherbert, Neo and others.

Having been flat out at work all day, I'm only just catching up on the very exciting events. Here is a quick after work effort relating features on the hi res swathe to their
likely position on the disc of Pluto. I say 'likely' because it was quite hard to tell but I went ahead anyway because I really wanted to try to find out! ……Hᴜɢʜ….ツ

Click to view attachment Click to view attachment

agreed. That terrain seems to result from compression from some tectonic force unless what we see is the result of ice sublimation leaving water bed rock exposed. 11000 ft high would seem too high for the latter.

I'd like to understand that conclusion better. The tidal forces on Triton from Neptune are in total about 20 times those on Pluto (please correct me if I'm wrong) from Charon, yet if you look at the dynamics, the forces are in a more concentrated band (angle) on Pluto compared to Triton. On average, Pluto actually has a higher temperature than Triton due to Triton's higher albedo. I'm looking forward to the temperature data, but current data has Pluto at 40 - 50K and Triton at about 35K.

Then again, Pluto has that 123 degree axial tilt, which means that the pole facing the sun gets much more insolation compared with Triton.

I can see that tidal heating is probably not the dominant factor on either body, but it probably remains as a factor. On the balance, Pluto "should be" more active than Triton .

Remember, we do not know the geologic history of Pluto system, but the clues to this puzzle are now in front of us.

Things have not always been as they are.

--Bill

Maybe solar heating together with precession of the polar axis can account for cracking. If there is a shift in the average insolation for the polar hemisphere due to that axis moving, thermal expansion at a hemisphere scale could be a powerful force.

What puzzles me is that similar surface features seen on other icy moons have shown topographies in hundreds of metres (correct me if I'm wrong) and not thousands of metres as seems to be the case with Pluto.

For anyone who (like me!!) may have missed the 15 July afternoon press conference there is also a link on YouTube
Now I am going to pour myself a beer, sit back and enjoy the excite-ment!!!! ……Hᴜɢʜ….ツ
Seeing Pluto in a New Light https://www.youtube.com/watch?v=0jTdaOhG9wE

I had the same thought. What I noticed was just how smooth (or reworked) the polar region is, but the high resolution images may totally change that initial impression. So I'll leave that comment in the parking lot for now.

What's next to be revealed? Cryovolcanic activity?

One clue is the smooth terrain in the equatorial region of Charon that could indicate a period of melting when tidal forces were significant. Curiously, the shoreline is tilted in latitude. That could be evidence of polar motion prior to the two bodies becoming tidally locked.

Don't think I saw this one posted:

Click to view attachment

(from here)

A link was posted (Post #438).

Here's a comparison with volcanopele's Post #266.
(I've darkened and sharpened the left-most map and rotated volcanopele's)
Click to view attachment

I've found one part of Charon particularly interesting. In the upper left quadrant of the press release image from yesterday (image taken on 7/14/2015) is what looks like a crater.

Click to view attachment

However, closer inspection seems to show that there were flows running from this crater (lower left of the image) - at least that is one interpretation. Cracks in the ice would be another explanation.

There is a bright area (bigger than a spot) near the middle of the crater. Based on the irregular horizon, it appears the area could be above the rest of the landscape. There appears to be maybe one other crater in the entire area.

So, my question is caldera or impact crater in the upper left quadrant of Charon?

Stereoscopic data would sure help in determining whether this region is above the immediate mean level on Charon or below. I guess all we can do is wait for more data.

Isn't it the other canyon that Emily mentions?

I believe that's just to the right of this area.

Andy

There is something that I don't understand about the Pluto pic.
judging from Emily's "What to expect when you're expecting a flyby" blog post it should be the pic returned in the First Look A:



but the resolution does not quite match it, and Pluto fills the frame. or it could be one from First Look B:



but First Look B data was returned during yesterday's press conf. so which picture is that? what is the resolution?

I posted about this yesterday. The close-up image we saw at the press conference was one of the images that was scheduled to be sent in the First Look B downlink. I guess that there was a last-minute change in the priority order of the images sent in the week after the flyby.

Thanks to the NH Team and great help from Alan Stern, we had great moments in Paris yesterday evening at our National Science Museum where the Pluto encounter was on live show.
Here are some quick snaps from the ambiance in Paris (from left to right and from top to bottom) :
Click to view attachment Click to view attachment Click to view attachment Click to view attachment Click to view attachment Click to view attachment
(i) the organizing team with myself, Gilles and Jean-Pierre ;
(ii) the full NH mission presentation where the important role of TPS for its lobbying at Washington D.C. to re-start the Pluto mission tender in 2001 was presented also ;
(iii) Richard Binzel (MIT) addressing the audience (and speaking fluent french) ;
(iv) a panoramic picture taken at the the start of the NH Press conference ;
(v) the introduction by Alan Stern ;
(vi) "OOOOOHs" ! "AAAAAAAAHs" !....
I'm sure that you enjoyed it as much as we did ! Wish you were here !

Thanks. there were 5 or 6 new pages in the topic when I woke up this morning and I must have missed your post!

Slapped together a quick 3D 360 spin of our favourite plutonian landscape:

http://youtu.be/37TNyDHZExA

It is worth pointing out that with Pluto and Charon strongly tidally locked, any perturbation to one of them will quickly transfer some forces to the other. in a somewhat non-intuitive fashion. Even a seasonal sublimation/deposition mass transfer on Pluto would create a mass shift that would generate forces on Charon, which would cause different forces back on Pluto.
This could be modeled and tested....

I agree with this (for whatever that buys you). It's kind of like ringing the bell one one side forces a bell to also ring on the other. While Pluto/Charon are small they aren't tiny so even a bit of movement at those temperatures could have a heating effect.

Andy

So, just to point out, one potential explanation for pluto's mountains that doesn't need to invoke any internal heat, is that they're pingos, allowed to reach great heights by pluto's low gravity. If that's the case then I'd expect the working fluid to be neon, as the base if the mountains will be under several MPa which would raise nitrogen's melting point too high (nitrogen could do similar closer to the surface... though its freeze-thaw is rather energetic!)

Basically, under this scenario, Pluto's resurfacing would be due to its elliptical orbit slowly shifting its temperature. Charon, having significantly less gravity, would experience the same effect at much gteater depths.

Agreed too. I have been considering something very similar.

If large 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, especially 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 orientation of this tidally locked binary planet system. This will create torque and cause a shift of the planetary axis as Pluto re-orients is mass distribution to the gravitationally lowest energy mode, and a subtle rebalance of the dynamics of the binary planetary system. This re-orientation of the axis should cause flexation of the crust, generating heat, which could be the internal heat engine.

Same goes for Charon.


247 year cycles, or longer phase cycles?


Needs modeling.

Water's peculiar property is that it expands when freezing. Isn't that necessary for pingo formation?

That source of energy would be traced back to energy introduced by solar insolation, but rather than directly heating the surface it would be a kind of second order effect to the system. Still, any heat generated through that effect would have to be equal or less than just pure insolation?

Interesting possibility. I wonder whether it is also possible that relatively moderate size impacts may deliver enough torque to Charon to disrupt the tidal locking (which is probably tenuous anyway) for a while. The process of reestablishing the lock can be a source of heating.

Yes, exactly. But that is a lot of energy even at Pluto's distance.

Internal mass re-distributions, like a mantle convection, would also lead to mutual tidal force transfer. One can speculate that if there was a large phase-change region internally, some sort of positive-feedback resonance could occur. and amplify the "churn". The point is, the mutual tidal lock generates interesting reactions to perturbations.

That's what I was trying to say a few pages back by saying we are incorrectly treating the Pluto and Charon bodies as gravitational point sources rather than as wider bodies. You said it much better than I did. Thank you!

The effects are subtle but add time (lots of time), an occasional good ringing and material transport will result in the gravitational energy providing some heating. It can't take too much heating at these temperatures to change these icy materials into slush.

One other quick note: I know this is obvious to all of us but this is the only mutual-tidal locked system any of us have seen (assuming we haven't been out of our solar system). Some reworking of the models would not be surprising.

Andy

The third "thing" just has to be a moon of one of the other two things already in a capture scenario, doesn't it? Since it seems that a lot of small objects can have moons in the asteroid and kuiper belts, I don't think it's that much less likely that Pluto could pass close to a pair of small objects rather than just a single one.

You say it's not very likely, but don't we think it already happened with Neptune capturing Triton?


It seems to me that the team have already decided beforehand that Charon must have formed in a giant impact, and I'm not terribly comfortable with that since I think that kind of conclusion can only be reached after looking at all the data - I don't see how they can be so sure of that from distant observations alone. I think we're really looking at two hypotheses here:

1) Pluto was hit by another object and Charon (and the other small moons?) formed from the debris. This happened long enough ago that there is no evidence for the impact on the surfaces of Pluto or Charon. Tidal despinning circularised the orbit and altered the surfaces of the two worlds before they locked with eachother.

2) Pluto captured Charon from another body that it passed close to. This happened long enough ago that the orbit circularised and Charon locked to Pluto. Tidal despinning altered the surfaces of the two worlds before they locked with eachother.

I think the only major issue with the second hypothesis is how the other moons fit in. Are they leftovers from smaller impacts on Pluto that happened afterwards? Are they also captured bodies (Kerberos seems different from the other small moons at least). But either way, the trick now is to look at all the data and figure out which one is the more valid hypothesis.

Have they pinned down the exact orbital eccentricities and inclinations of all the moons? If not, they should be able to from the data they've got from the approach and flyby.

I don't know about neon, but freezing liquid nitrogen (due to pressure drop) likes to form a foam of far greater volume than the liquid, at least when not under pressure. It also undergoes a glassy ->crystalline phase change with a rapid change in volume.

The basic point, though, is that there could be some very dramatic frost heaving effects caused purely by orbital temperature/pressure changes. These mountains may be the height of the rockies, but they're only the weight of a <100-meter hill (per unit area)

Wonderful hypothesis, I have been wondering how Pluto could have this kind of cryogenic "geology" we're gotten hints of in the high resolution frames. And a thank you to JohnVV for the processing which give an idea of relative hights also. If your line of thinking is correct many phenomena might be possible, even Pluto quakes.

I saw the Youtube video, and I do not think that it applies at all to Pluto.

In the Youtube experiment, the phase transitions being displayed was liquid N2 was being supercooled and flash frozen into a glass. The subsequent transition from glassy N2 to cystalline N2 was energetic, and caused disruption of the glass as crystals formed, and was fairly energetic.

However, in the case of Pluto on the surface, the phase transition would be gas to solid N2(g) -> N2(s), and this process would be layer-by-layer deposition. I would not expect this to deposit from gas to solid as a glass unless the deposition rate was extremely fast. Even then, if there were any crystalline N2 on the surface prior, then ongoing subsequent deposition onto an existing crystalline N2 would maintain crystallinity, and not form a glassy solid N2. Thus no opportunity for the energetic glassy - > crystalline N2 transition.

In the putative case of an underlying sea of N2(l) which putatively freezes, I also would not expect it to flash freeze as a lake of glassy N2. All it would take is one seed crystal of cystalline N2 somewhere to seed the freezing to go directly to crystalline N2. Presumably, the layer of frozen N2 over the putative lake would be in the crystalline form already, so any additional N2 freezing would continue to form additional crystalline N2, not glassy N2. Thus no opportunity for the later energetic glassy - > crystalline N2 transition.

From the Heart photo & fredk's placement of the frame on it, it looks like the hummocks are caused by an impact crater just off-screen in the frame, visible at the bottom of the full disk image. I don't think we've seen wavey ejecta like that before though, so it could the crater is just lying atop previously hummocky terrain...

http://www.nasa.gov/sites/default/files/th...frame_color.jpg

We should know more about crater morphology once we get the frames to the left of Tombaugh Regio, there's a few decent sized craters there.

I am wondering if the crater-counting method of judging the age of a surface needs to be 'calibrated' for the far outer planets differently than it is for the inner ones.

The KBOs probably outnumber the Asteroid Belt objects, but they are so spread out, and without Jupiter stirring the pot so much during the Heavy Bombardment, maybe the density of collisions was less.

Hm, but on the other hand if Pluto/Charon had a past close encounter (and maybe even Pluto/Neptune) perhaps my hunch is wrong.

See "Cratering rates in the outer Solar System", Zahnle et al.
http://adsabs.harvard.edu/abs/2003Icar..163..263Z

I feel that a Probe that visited Pluto during perihelion would have seen a very different Pluto.
Imagine, Summertime on Pluto? Again, imagine aphelion ???

Neptune has the largest Hill Sphere in the solar system, with a radius of 116 million km. It could potentially capture something due to an impact taking place inside that sphere.

Pluto's Hill Sphere is 1/3000th the volume of Neptune's.

It's not impossible, but it's a lot more likely for one thing to hit Pluto than it is for two things to hit, in just the right way, while near Pluto.

Since the entire system with Charon and the other moons is in the same plane, it seems exceedingly unlikely (or impossible?) that Charon was captured as it is now. The entire system seems to be the result of one impact event. Any moons that existed before the impact would likely have been ejected from the system.

But I'm just an armchair amateur, so I could be very wrong.

I just discovered Pluto ski T-shirts are available online. Do you all think those mountains we saw yesterday would be good for skiing? I'm sure there would be some black diamonds.

The downlink completed during the press conference:



The LORRI image we saw (of the mountains on Pluto) was probably early in the downlink queue for First Look B, so it could have been down many hours prior to the press conference (the entire downlink took 6.9 hours).

Right. And that makes the linear trough(?) that Explorer1 noticed (which runs diagonally through the hires frame) run roughly radially to the crater. No idea if that helps make sense of all this.

I should have used a few more adjectives - I meant capstone in a loose earth analog sort of way - Pluto clearly doesn't have rain and doesn't need a hard crust, and I think it is a capstone only in the sense of an insulating dust/Thollins blanket which caps the sublimation - I doubt it is very hard, just insulating/protective. Since some sublimation would happen in less dusty/Thollinly areas - there would be half height mountains with some dark top coating. For the peaky already eroded Mesas - a dark residual coating on the sides of the mountains which fell down the sides as the white mountain material sublimated away would be expected and is visible in the pictures.

One thing that I wonder is the scientists assertion that it has to be water ice mountains to sustain an 11,000ft mountain - if the entire surface were packed frozen nitrogen (or something else) for instance and the base ground eroded - one can get taller structures via erosion then would be expected in a building process (again see the mesa remnants with their unlikely tall pillars). Hopefully we will have enough resolution to figure out the composition of the mountain slopes in the upcoming data.

As someone who has been following a Pluto mission of some sort (first proposed, then actual) since the early '90s, I want to send out my sincerest thanks and congratulations to Stern and everyone else involved in New Horizons. As some others have already posted, I was too young to appreciate the Voyager encounters, so this mission has (and will continue to be) a source of unique interest and excitement. Again, bravo!

New image of Charon, can't find the source yet.

https://pbs.twimg.com/media/CKDWGJKUkAAjcuQ.jpg