New Horizons: Near Encounter Phase Options

[nprev]

I think so, and others have asked about it as well. I haven't seen it.

[machi]

Does it state anywhere which filters did Ralph use for the false-colour image? i.e. are they infrared/visible/UV wavelengths, or are they just visible colours enhanced in saturation?

MVIC uses blue, red, near infrared and methane filter (also in infrared part of spectrum).
So those are definitely not visible colors enhanced by saturation.
My version has colors pushed more to the blue part of spectrum and it's interesting that this doesn't changed Charon's appearance.
Based on that I suppose that they used one of the infrared filters as red color.

[HughFromAlice]

Post #249 Great images, just to let you know, the caption says "spacecract" EDIT: I've just thought, WHO IS LOOKING AT THE CAPTION !!!!!

OMG! Thanks for pointing that out. I've just uploaded a corrected pic. I was doing this at 1.30 am in the middle night, with half my brain thinking that
I had to get up early the next morning! My bush story is that Central Australian spelling is known for its 'phonemic elasticity'!! ……Hᴜɢʜ….ツ

[Don1]

Speaking as a lazy biochemist, I've noticed that old, polymerised cyanide solutions make a nasty brown/black gunky mess. Digging around in the literature I found the following: "Adv Space Res. 1992;12(4):21-32. Hydrogen cyanide polymers on comets." I wonder if similar will be found on Pluto.

I think it is very likely that similar will be found on Pluto. Some comets come from the Kuiper Belt. I'm not really comfortable with calling them hydrogen cyanide polymers. In organic compounds, C-N groups are called nitriles, as I'm sure you know. Acrylonitrile is a feedstock for manufacture of a common plastic called ABS, which I think is what the keys I am typing this are made of.

According to the research I've read, tholins (the common non-iron reddish materials in our solar system) are believed to be predominantly PAHs (polycyclic aromatic hydrocarbons) ...

The thickness of a floating ice cover required to reach nitrogen's triple point is not that incredible. It's the weight equivalent of less than a meter of ice on Earth.

PAHs contain sheets of C atoms made up of 6 membered rings, with a special type of bond called a delocalized bond. Compounds with these delocalized bonds are usually called aromatic compounds. PAHs tend to be black compounds, and are common in crude oil, asphalt, soot and burnt toast. I'm sure that tholins contain plenty of aromatic rings, but I don't think they are directly equivalent to PAHs.

The problem I have with the floating ice idea is that the ice needs to be free of cracks in order to hold pressure. Naturally formed ice and rocks tend to contain abundant cracks.

[Nafnlaus]

[quote name='Don1' post='223394' date='Jul 14 2015, 10:52 PM'
The problem I have with the floating ice idea is that the ice needs to be free of cracks in order to hold pressure. Naturally formed ice and rocks tend to contain abundant cracks.[/quote]

Not at all. Does Europa's ice need to be free of fractures for the subsurface ocean to exist? If a crack in such a situation forms, liquid will fill it and freeze.

[MarkG]

Pluto sure looks like a place where aeolian "ice" transport has been taking place, most likely with multiple ice chemistries. One thinks of the South pole of Mars, where water ice is overlain with carbon dioxide ice.
The west half of the "heart" resembles a giant impact basin that has accumulated one type of ice, with another type alternately condensing and subliming. The east "heart" and area to the south seem to have aoelian-flow-like bright areas (deposits?). related to the western "heart".
As far as tectonics goes, there is a tiny solar tide, but there might be some induced forces as the moons adjust to the (very slow) precession of Pluto's axis. (Anyone have the precession period handy?) This also affects which hemisphere has summer during perihelion, and how long that takes to switch.
Pluto is real, and wierd to boot!

[JRehling]

Another look at the Heart, and why it seems so puzzling: I'm starting to think that flow occurred, strangely enough, in both directions, inward and outward.

The interpretation I'm starting to favor is that the western Heart is a basin. Dark intrusions on the northwest border may indicate that viscous flows came down into it, liquid enough to flow, but viscous enough to remain elevated relative to their surroundings to each side.

Then the bright material making up the current surface of the western Heart filled it, embaying many of those dark peninsulas and even creating islands in places. That could be dust or liquid, but it was less viscous than whatever material makes up the dark peninsulas.

[Don1]

Not at all. Does Europa's ice need to be free of fractures for the subsurface ocean to exist? If a crack in such a situation forms, liquid will fill it and freeze.

Europa's ice cover is much thicker than a few meters, and yes it does need to be free of fractures for the subsurface ocean to exist. Leaks may well be self sealing, because the escaping liquid will cool as it vaporizes and will turn into a mixture of ice and vapor.

That raises the question of how thick the ice cover has to be for it to be self sealing? The pressure needed for liquid nitrogen on Pluto is quite a bit higher than the pressure needed for liquid water in warmer regions of the solar system.

[nogal]

And by now, 23:38 UTC, the Phone Home signal should have crossed the orbit of Saturn
Less than 75 light-minutes to reception

Fernando

[Don1]

Another look at the Heart,...
... viscous flows came down into it, liquid enough to flow, but viscous enough to remain elevated relative to their surroundings to each side.

Solid materials can undergo plastic deformation. Water ice does it in glaciers and ice sheets. Organic polymers are notorious for this kind of behavior.

[Sherbert]

Great images again ZLD. I had a look back at those experimental images you posted and a few of the features picked out well on those images can be sen as real on todays fabulous image. In particular at the boundary of the giant bright foot (not heart anymore), where there were strong indications of some mountains along the western edge of the bright region and a clearly evident crater nearby. This image shows that area. If that really is a mountain as the shadows suggest, it must be huge, miles high, along with the cliffs along the edge of the whales head. What could force the surface of a basically flat world that high?

https://www.flickr.com/photos/124013840@N06...eposted-public/

Even in this image that gleam noted by others stands out. Given the Sun angle my thought is its just a small exposed bit of icy subsurface, where maybe more rapid sublimation has displaced the thin coating of dust/organics as suggested occurs on the surface of 67P.

It was suggested above, maybe the "foot" is where Charon impacted Pluto. If it was a glancing contact moving South to North, a gouge in the terrain would form like a Halfpipe ski course and surface material pushed ahead in an irregular hemisphere raising up a huge cliff, the toes of the foot. This low lying, cold basin would rapidly become filled with freezing super volatiles, if really deep, even liquids with ice on top. Being near the equator maybe it was too warm for Nitrogen to freeze, so preferentially Carbon Monoxide froze here. Interestingly the circular ice cream blob in the cone is almost directly in line with Charon on the far side of Pluto. As a result there would be an atmospheric tidal bulge in this area, increasing the thickness of the atmosphere and the vapour pressure at the surface. More reasons for increasing the fractional freezing of the atmosphere.

Others have also mentioned sublimation erosion and sublimation features. The features in dark area below the large mountain(?), in its shadow essentially, look exactly like those on 67P, but elsewhere in the whale feature, its almost featureless. Perhaps a little microclimate in the shadow of the cliffs is just right for sublimation to occur of a particular molecule, Neon maybe. I am pretty convinced now the dark equatorial regions are akin to desserts such as Death Valley, deep depressions in the shadow of mountains, where radiation has created a thick coating of complex organics, PAHs as mentioned and Thollins, are likely candidates. It will be interesting to compare the spectra to the dark surface of 67P or Ceres, I have a feeling they will be similar. The dark, energy absorbing, insulating surface covering, inhibits sub surface sublimation and frozen volatile deposition. Essentially the surface remains unchanged and the dark surface layer very, very slowly, gets darker and thicker.

Finally to the false colour image. The pale blue areas look to me to be recent frost deposits, maybe of Nitrogen, they appear to be located in the colder valleys between the darker hills and ridges, where sublimated ice has left organics and dust residue, which helps keep these higher areas slightly warmer by absorbing more sunlight. The topology and illumination conditions appear to be critical in controlling the fractional freezing and sublimation of the different species within Pluto's atmosphere. Pluto is a giant experiment in fractional distillation of super volatile ices, if that makes sense with no liquid phase involved.

[4throck]

Guessing that the color image is IR R B , I've processed it as R (G=0.5R+.5B) B and I get this:



Levels adjusted so that brightest ices are white. Certainly looks less psychedelic!

[nogal]

July 15 00:16 UTC, the Phone Home signal should have crossed the orbit of Jupiter.

NASA TV transmission should be starting soon.

Fernando

[MahFL]

I have no idea if the data includes the amount of occupied memory.

She said the phone home signal will indicate which sequences ran ok, whether there had been any computer resets and the amount of the recorder used.

[dvandorn]

I believe the NASA TV program has been shifted back an hour, so won't be starting for more than an hour. The description of the program was also changed, from some general description to saying it would specifically be a press conference.

-the other Doug