Jason Cook along with 10 other scientist like Alan Stern, Harold Weaver & Will Grundy recently released a significant paper about Pluto's Moons Styx, Nix and Hydra called Spectroscopy of Pluto's Small Satellites. The paper reveals they all have ammonia hydrates (the moons not the scientists :-).
Ammonia is NH3 or 3 Hydrogen atoms bonded to a nitrogen atom (plenty of both elements on Pluto). A Hydrate is a substance that contains water H2O |
Carl Sagan & Bishun Khare were the two scientists who combined these gasses commonly found in the universe with simulated electrical pulse lightning to develop the complex hydrocarbons we call tholins. Tholin's are the red gunk on Pluto, the impact crater zit on Nix, the red stuff on Charon's north pole called Mordor and the red material found on comet 1994 Jr1. |
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Four hydrocarbons identified in Pluto's atmosphere. Methane (CH4), acetylene (C2H2), ethylene (C2H4) and ethane (C2H6). |
The melting temperature of ammonia hydrate at 1 bar is ~194 K (Pluto's surface temp is 30-65K and its atmospheric pressure is 100,000 times less than earth, similar to Mars.), considerably lower than that of pure water ice.
On a saturnian satellite, photolysis would deplete a 10 micro meter layer of ammonia rich ice in only 100 years, and sputtering would deplete the uppermost surface layer of any ammonia molecules on time scales of less than a million years (Saturnian moons are closer to the Sun than Pluto delivering more photons=less time to deplete NH3+H2O). Therefore, the presence of ammonia hydrate on the surface of an icy satellite implies recent emplacement, possibly by cryovolcanic activity. Such activity has been invoked to explain the presence of ammonia hydrate on Pluto's satellite Charon. We find that spectral models (red line in Fig. 1) which include as much as 80% by weight of ammonia hydrate (1% NH3.H2O) intimately mixed with water ice at 60 K covering 30% of the illuminated surface area fit the observed spectrum. |
Ammonia has an interesting characteristic trait, it is quickly destroyed, taken apart or disassembled by the Sun's light in a process called photolysis or photodissasociation.
In other words photons of light break down the NH3+H2O bonds, it separates the ammonia from the water ice and the hydrogen from the nitrogen. |
The presence of ammonia means Charon's smooth southern surface could have occurred less than 20 million years ago as did the formation of the small moons.
(Update Jul 2018, Charon's entire leading hemisphere both north and south display blotchy patterns of ammonia, indicating the ammonia is not a usable age dater for the smooth southern hemisphere) If these small moons were older than 20 million years there would be no detectable NH3+H2O (NH4+OH). In an effort to explain why the small moon's reflectance or albedo is so bright after 4 billion years, NASA postulated micro meteorites were continually cleaning or resurfacing the moons. |
"Clean surfaces" mean the surface is exposed to photons from the Sun and the ammonia would then be disassembled within 20 million years. The albedo of these moons are bright because they are young and the ammonia hydrates support this concept. They could not have formed in situ from an accretion disk of small particles of debris 4 billion years ago during a Pluto/Charon collision. There's no mechanism for renewing the ammonia hydrates on any of the moons they are all dead geologically. Other neighboring Plutinos are much darker (low albedo) than Pluto's moons, if micro meteorites were the cause of the high albedo of Pluto's satellites then those micro meteorites would perform the same cleaning function on other Plutino's. Only Pluto's moons are this bright. On the other hand, if these bright moons were more recently knocked off Pluto/Charon into full sized moon chunks, it couldn't have been that long ago or else the ammonia hydrate would have disassociated. That means these small moons or at least their surfaces are much, much, much younger than 4 billion years. |
Another possibility is that I don't understand this information and am getting something wrong but I don't think so, it simply took me a long time to find the right scientific data to back up what I've been saying about the active geological age of Pluto and Charon.
This stuff happened recently and there is no radioactive hot core. One reasonable explanation for all these observations is that Pluto and Charon experienced a recent (less than 1 byr) elliptical tidal flexing Neptune induced eccentric orbital dance. Even though the small moon's display surface materials that are less than 20 million years old, the eccentric elliptical dance between Pluto and Charon would have begun further back in time say 500 to 700 million years ago but the moons could have come into existence recently by the impact at Mordor releasing Charon's pent up pressure which was created by the elliptical tidal flex energy. |
The one moon missing from this reported NH3 information is Kerberos. It was too far away and too small to get a good enough read to determine whether or not there is NH3 on it. Since Charon, Styx, Nix and Hydra have ammonia hydrate's it is very likely Kerberos contains NH3 as well. Whether it does or doesn't is mostly insignificant. |
The above chart on the right has 3 diagonal lines indicating surface age.
yellow=4 byr, blue=3 byr and purple= 2 byr surfaces. Hydra's 3 blue triangles fall between 2.5 billion years and about 2.75 billion years Nix's red/pink diamonds depending on the camera used ranges from 3 to beyond 4.5 billion years. So the range of potential ages for these moons based on NASA's chart is anywhere from 2.5 to more than 4.5 BILLION years that's a 2 billion year slop factor. Yet NASA claims this as proof the moons are 4 billion years old. This chart to the left from a New Horizons team paper called "The Small Satellites of Pluto as Observed by New Horizons" shows the Nix impacts (pink & red diamonds) not shown in the above chart. These impact examples don't fit as nice and neat into this 4 billion year old theory so they were left out of the black chart above which was used by Kelsi Singer at the 47th LPSC conference in Texas. |
This new information about these small moons kills one Pluto concept of mine. I suggested that since we don't see ammonia on Pluto, it is not reasonable to assume it's present below the surface (turns out it was a reasonable assumption). I further stated that just because we see it on Charon doesn't mean it exists on Pluto. While that statement is correct, if we see it on Charon, Styx, Nix and Hydra, which now we do, then it is very reasonable to assume it exists on Pluto below the surface but was not detected because of active geology. |
There are two ways of adjusting my theory to align with this new information about ammonia found on three of the small moons. Either Nix is not a rock of ice ejected from Pluto (perhaps it came from Charon) or Pluto does have ammonia but just not detectable on the surface. Either way, this is significant information and in either case one of my theories is incorrect.
I've suggested two theories followed by a prediction the prediction was wrong which suggests one of the theories was also wrong. Theory 1, Hydra was kicked off Charon - rational -
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Since Nix looks, smells and barks like a Pluto (similar albedo, red zit, low orbit), I'm going to continue to say it came from Pluto not Charon.
Since Nix has ammonia, it may have come from Charon but the albedo and tholin zit crater argue against this so I'm tossing this idea aside in favor of Pluto having ammonia. Conclusion, Pluto has NH3 because Nix came from Pluto and has it. |
While the required subsurface pressures could be achieved to produce an ocean of water and the ammonia does exist (in unknown quantities), the core is not large enough to be hot.
Without a large and hot enough core to produce sufficient heat, it is still an unlikely scenario to assume there is a water based ocean. Since I don't know if tidal flexing could have generated enough heat energy to create the pressures and temperatures required to turn ammonia infused ice into liquid water, I keep falling back to observational evidence. |
If the mere presence of ammonia was enough to argue in favor of a subsurface ocean of water, Charon wouldn't be dead.
We see NH3 on the surface of Charon but it is not geologically active because it is too cold, too small with too low a density to have an active core hence no ocean of water and no geological activity no atmosphere. Green blotches and freckles in this image are the detected NH3. |