Dunes.
And basins.
Maybe not as thoroughly chemically processed as Titan's basins, but basins.
What do you think New Horizons will find at Pluto? How will Pluto surprise us?
-Mike
One or more very small previously undetected satellites.
I like http://www.unmannedspaceflight.com/index.php?s=&showtopic=265&view=findpost&p=1233
I think we're going to see a really diverse mixture of surface ages underlying the seasonal frosts. There will be four main surface types: (1) really old cratered regions (both bright and dark) that resemble Iapetus, (2) faulted regions (like parts of Enceladus, Ganymede etc) and (3) Triton-like 'cantaloupe terrain'.
What about type 4?
I think there will be a major difference between the terrain on the hemispheres of Pluto & Charon facing each other and the hemispheres facing away. As Earth-Moon is perhaps our best analogue for this kind of situation I will say that these facing hemispheres will have cryovolcanic maria.
My image is always a frozen-out Titan
A planet
Well, I guess we'll see something like Europa, but heavily cratered and much dirtier.
I think Pluto will be ancient & cratered with little else.
Triton was most likely a captured Dwarf Planet by Neptune. During capture the orbit was very elliptical, thus raising huge tides that heated up the interior (much like Jupiter with Io), initiating massive cryovolcanism that resurfaced Triton. When the orbit settled down, tidal flexing reduced & a new surface froze.
Pluto, as far as is inferred, has never undergone such heating. I think a Triton, Europa, Enceladus, Dione, Ganymede, etc type surface is just wishful thinking. Sure there are ices present & these ices may migrate dependent on the season & the point of the elliptical solar orbit, but Pluto & for that matter the larger & more massive Eris do not appear to have been subjected to violent heating that Triton had.
I think Pluto will look more like Callisto, Rhea or Iapetus. Mostly craters, with perhaps a few fractures. I may be wrong, but that's exploration.
Andrew Brown.
I'm not so sure that Pluto is inactive. Observations by the Gemini Observatory in 2007 suggest that Charon may have cryo-volcanos. Since the two objects are tidally locked and relatively close in mass, I wonder to what extent they keep each other geologically active. It certainly will be interesting to see what plays out!
My guesses,
Pluto may be found to have been active in the past.
I expect Pluto to be more heavily cratered than Charon.
Nix and hydra, will probably resemble Phobos and Deimos--dead, cratered rocks.
I'm thinking there might be a sort of Hellas basin on Pluto. An impact would nicely produce a bunch of little moons.
I'm expecting Charon to be slightly active, and Pluto effectively dead.
I'm expecting to see strong tectonic effects on both Pluto and Charon. I think tidal effects will have caused a lot of surface disruption on both bodies.
I also think it's possible that Charon, at least, may resemble Umbriel as a body that has been roughly re-assembled from the crushed remnants of an earlier body. The total angular momentum of the Pluto-Charon system resembles that of the early Earth-Moon system, which supports the idea that Pluto and Charon have a similar big whack kind of history. Pluto may show some very interesting signs of a post-impact redifferentiation, but Charon may be just below the size limit to have re-differentiated. It all depends on how long ago their big whack occurred, and the materials involved, of course, and while we have some hard compositional data, it's not exact enough to plug into a pretty formula and get Pluto/Charon out the other end.
So, I expect to see what we're going out there to see -- something unlike anything we've ever seen before.
-the other Doug
I think that Mars is to Earth as Pluto is to Titan.
I imagine Pluto as an older and colder version of Titan.
I wonder if at some point in the far deep past that Pluto had a substantial nitrogen atmosphere and might've gotten warm enough to support a nitrogen ocean. Maybe there is a possible scenario where Pluto had a full meteorological cycle involving nitrogen (azatological cycle?). Nitrogen rains condensing out onto a frozen hydrocarbon surface, carving out channels, filling in basins, and making dunes from hydrocarbon sediment blown in a nitrogen wind. Then over time the nitrogen was lost, or froze out, and everything dried up.
The tidal effects of Charon may give Pluto two different faces. A warmer one towards Charon due to tidal effects, and a colder one facing away from Charon. The cooler one probably looking older and more crater-ridden (and maybe covered in nitrogen frost that moved from warmer hemisphere to the colder one.)
While Pluto will be surprising, I'll bet Charon will be fun.
-Mike
Okay, I'll bite.
Charon will look a lot like Dione. Mostly cold and dead with a few large impact basins. Extensive tectonic fractures will be visible on the sub-Plutonian hemisphere, but billions of years have passed since those fractures were last active.
Pluto will look quite similar, but the effects of a thin atmosphere will increase the rate of erosion, smoothing out a number of older impact basins. New Horizons will spot a number of flow-like features, leading to a huge debate over whether those features were carved by ancient cryovolcanism or from nitrogen/methane flows from a time when the atmosphere may have been thicker.
Um, yeah.... Miranda, that's the ticket...
the other Doug
Hmm. Interesting thoughts here from VP, oDoug & Hungry that I'll shamelessly derive from:
Pluto will look like one of the midsized Saturnian moons...sort of like Tethys, actually, with more weathering from the presence of a periodic atmosphere, low topography from an episode of global crustal melting, and perhaps even a slight resemblance to Vesta with a big honkin' oblique crater as an artifact of the event that produced Charon, Nix, Hydra & any as yet undiscovered moons.
Sorry, but can't buy off on the Miranda possibility...too many orbits (and too much distance traveled; thinking fragment trajectory divergence over time) needed to put Humpty-Dumpty back together again, if that is indeed the correct explanation for Miranda's appearance.
For what it's worth...
I expect Pluto to be Triton like mixed with a dash of Ganymede.
And Charon similar to Ariel.
PS I expect something totally unexpected as usually. The 2 newer moons I believe with be very interesting.
I don't know, but I'm sure it will be informative even if it's "just" an ice ball.
Cryovolcanos and a gravity center outside both bodies could produce something interesting. Is it physically possible that moonlets like Nix and Hydra formed by aggregation at the gravity center and then migrated to their current orbits?
After such an impact, there must've been an aweful lot of tidal friction generated on both bodies as the system locked up into its current configuration. How much heat would have been generated, and how would this have affected the crust and surface of Pluto?
Even now, how much tidal libration is in the system? (How eccentric is Pluto-Charons orbital couple?) And would this tidal energy get evenly distributed or would there be sub-crustal hotspots at certain points?
-Mike
After thinking about this a bit more:
If the giant-impact model of Charon's formation is correct, it's likely that Charon formed quite a lot closer to Pluto than is the case today. This means that it may originally have had an "egg-shaped" profile (similar to Mimas) caused by tidal effects.
Eventually, Charon moved outwards, and the system reached the mutually-tidally-locked configuration. However, with Pluto's mass being so small, I wonder if Charon's orbital evolution could have proceeded slowly enough for the moon to solidify completely before it reached its current distance from Pluto?
If that's the case, Charon may show some features characteristic of relaxation of an initially ellipsoidal solid body to a more circular shape. Sort of a reverse version of what happened to Iapetus, maybe?
2010 Hydra-Nix Meeting Webcasts May 11-12, 2010
https://webcast.stsci.edu/webcast/searchresults.xhtml;jsessionid=FEEF69927476DCB92A6E2AD7BA6A2EE0?searchtype=20&eventid=129&sortmode=1
Unfortunately, English is not my native language. I have a problem with understanding the spoken english language. Maybe you can find here some interesting information about Nix and Hydra.
Didn't Hubble see an atmosphere when Pluto was closer to the sun? If so, might NH see evidence of that atmosphere refreezing and recently falling back to the surface?
Recent observations indicated that there might be a lag in the freeze out of Pluto's atmosphere. It might be just starting to freeze out as NH buzzes past.
From Pasachoff et al. The Astronomical Journal 129 (2005) 1718-1723. "The structure of Pluto's atmosphere from the 2002 August 21 stellar occultation."
Freely available http://74.125.155.132/scholar?q=cache:EKui1sTcqwUJ:scholar.google.com/+Pluto+atmosphere+pressure+altitude+plot&hl=en&as_sdt=40000000000. (as html, click for pdf version)
"The current increase in temperature and pressure seems to prolong the period in which the atmosphere will remain detectable before its collapse, making it more likely that New Horizons will be in time for atmospheric studies at Pluto. The current data are consistent with the model of Hansen & Paige (1996, Fig. 11) that shows a cooling beginning in 2015, not far from the spacecraft’s prospective arrival."
I hope that doesn't mean we're likely to be there on a cloudy day!
--Greg
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)