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Pluto Surface Observations 3: NH Post-Encounter Phase, 1 Feb 2016- TBD
hendric
post May 24 2018, 04:49 PM
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Wow, that's practically...uh, dense? smile.gif Definitely enough for lots of interesting things to happen! dd.gif

edit: Aw man, the dust devil emoticon is broken. Can we get that fixed?

Admin- Yep! smile.gif


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HSchirmer
post May 24 2018, 11:51 PM
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QUOTE (hendric @ May 24 2018, 04:49 PM) *
Wow, that's practically...uh, dense? smile.gif Definitely enough for lots of interesting things to happen! biggrin.gifd:


Wow. 18-280 millibars?

So, thats 3x Mars (low estimate), or roughly equal to the top of mount everest (high estimate).
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Explorer1
post May 25 2018, 01:34 AM
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How far would the atmosphere have extended in scale height beyond the modern level? Perhaps the tholins of Mordor Macula on Charon were all deposited during this period? Or could the molecules have jumped the gap throughout Pluto's history?
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Gladstoner
post May 25 2018, 02:00 AM
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QUOTE (Alan Stern @ May 24 2018, 09:05 AM) *
Our paper sets a limit near a few hundred millibars for Pluto.


Thank you Alan. I look forward to reading the paper when I can find sufficient time.

As others have mentioned here, a few hundred millibars could allow for many interesting processes to potentially occur on the surface.

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Daniele_bianchin...
post May 25 2018, 02:48 PM
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QUOTE
I do not know if this is the right place. I watched this Pluto area. What is these like rivers?
nitrogen ice flows?

http://www.unmannedspaceflight.com/index.p...st&id=42956

Sputnik planum could be in the past an exposed ocean of liquid Nitrogen as is the case with Titan\'s methane oceans?
can a planet or dwarf planet exist with an exposed ocean of liquid nitrogen?
how big must a planet be to have a liquid nitrogen ocean??
Grazie


QUOTE
Back in 2011, there was a suggestion that rivers of liquid nitrogen might be stable on Pluto
http://www.planetary.org/blogs/emily-lakda.../2011/3182.html

That was followed up by 2016 announcements that when Pluto\'s orbit and rotation are just right,
Pluto\'s atmosphere should support an atmosphere thick enough for liquid nitrogen to flow.
http://www.unmannedspaceflight.com/index.p...mp;#entry229510


That means surface temperatures must be fluctuating enough to mess with the nitrogen on Plutoís surface, driving it from a frozen solid into a gas. And sometimes, the temperature and pressure occasionally rise high enough for liquid nitrogen to flow on the surface.

The last time temperatures were sufficiently high to melt nitrogen was around 800,000 years ago, when Plutoís orbital alignment led to its most extreme warm climate, says MITís Richard Binzel.
[/list]


To be rivers and lakes of Nitrogen there must be a cycle of Nitrogen like that of Methane on Titan? So there was a dense atmosphere with clouds and rains of nitrogen over Pluto?
Sputnick planum was a surface liquid nitrogen ocean that is frozen today?

Chemistry and physics manage to create surprising little worlds, like Titan and Pluto.
We find many more features of movement and geological activity in cold worlds than in hot worlds. When I look at Pluto I see the characteristics of a great world ..
I am surprised when I remember that he is smaller than our Moon.
I like to think that the cold does not give life, but the too cold, inconceivable, start strange processes.
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HSchirmer
post May 25 2018, 04:06 PM
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QUOTE (Daniele_bianchino_Italy @ May 25 2018, 02:48 PM) *
So there was a dense atmosphere with clouds and rains of nitrogen over Pluto?
Sputnick planum was a surface liquid nitrogen ocean that is frozen today?


Clouds and rain, probably.
Dense is relative 18-280 millibars might be considered dense in astronomic terms,
but humans need a pressure suit (IIRC) below ~50 millibars or your body temperature boils you blood into vapor.

As to Sputnick planum, I tried a basic estimates (e.g. an order of magnitude) that the amount of nitrogen locked up as ice in sputnick planum
seems to be roughly equivalent to the amount of nitrogen that a warm period Pluto would need for an atmosphere to be in thermal equilibrium.

If the real scientists estimates are 18-280 millibars, then I'll defer to them that there is enough near surface N2 to support a 280 millibar atmosphere.
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Daniele_bianchin...
post May 25 2018, 04:16 PM
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QUOTE (HSchirmer @ May 25 2018, 05:06 PM) *
Clouds and rain, probably.
Dense is relative 18-280 millibars might be considered dense in astronomic terms,
but humans need a pressure suit (IIRC) below ~50 millibars or your body temperature boils you blood into vapor.

As to Sputnick planum, I tried a basic estimates (e.g. an order of magnitude) that the amount of nitrogen locked up as ice in sputnick planum
seems to be roughly equivalent to the amount of nitrogen that a warm period Pluto would need for an atmosphere to be in thermal equilibrium.

If the real scientists estimates are 18-280 millibars, then I'll defer to them that there is enough near surface N2 to support a 280 millibar atmosphere.

Thanks hschirmer!
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Superstring
post Jun 1 2018, 11:55 PM
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Methane ice dunes on Pluto
http://science.sciencemag.org/content/360/6392/992

I've been searching for estimates of the surface area extent of the dunes and their heights, as I'd like to compare to the dune coverage on Venus, Earth, Mars, and Titan. Does anyone have that information or want to take a guess?

Also, this discovery makes me even more eager to see Triton in higher resolution...
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dolphin
post Jul 3 2018, 05:17 AM
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QUOTE (Superstring @ Jun 2 2018, 12:55 AM) *
Methane ice dunes on Pluto
http://science.sciencemag.org/content/360/6392/992

I've been searching for estimates of the surface area extent of the dunes and their heights, as I'd like to compare to the dune coverage on Venus, Earth, Mars, and Titan. Does anyone have that information or want to take a guess?

Also, this discovery makes me even more eager to see Triton in higher resolution...


Will E-ELT be able to resolve the chevrons on Miranda, geysers on Triton, etc?
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hendric
post Jul 9 2018, 09:14 PM
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Per their FAQ, their expected resolution with adaptive optics is 5 milliarcseconds, which is ~2.4E-8 Radians.

radians * distance = ~resolution

Uranus distance resolution
~70 km

Neptune distance resolution
~110 km

Pluto distance resolution
~143 km

So I think E-ELT would be able to resolve ~7 pixels on Miranda. Triton is 2,700 km wide, so it would get ~24 pixels.


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"The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke
Mother Nature is the final inspector of all quality.
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Roman Tkachenko
post Jul 14 2018, 02:02 PM
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Happy Anniversary, New Horizons!

Pluto and its Elliot Crater (Simulated perspective view)


Pluto's Hayabusa Terra (Simulated perspective view)


Pluto's Tartarus Dorsa region (Simulated perspective view)


Pluto's Tenzing Montes at Twilight (Simulated perspective view)


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Explorer1
post Jul 14 2018, 02:28 PM
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Incredible work! Like we're really there!

The last one is especially interesting, considering Earth and the Moon transited the Sun as seen from Pluto just last week.... won't happened again for a century and a half. We certainly won't have better views for a long time.
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MarcF
post Jul 14 2018, 08:15 PM
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Two amazing articles about the cartography and topography of Pluto and Charon in Icarus journal, by Paul Schenck et al.
Pluto:
https://www.sciencedirect.com/science/artic...019103517306024
Charon:
https://www.sciencedirect.com/science/artic...019103517306565
A lot of data, many illustrations and many discoveries.
Thank you for this great work Paul. Fantastic as usual !
Regards,
Marc.
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Phil Stooke
post Jul 15 2018, 05:31 AM
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I was planning to draw attention to those papers as well. It's true, they are amazing. The thing I keep thinking of is how far ahead we are now compared with Voyager 2's flyby of Neptune and Triton. In some ways the Neptune and Pluto systems are similar (not in sizes but in number of targets) and the fast flybys were similar in timing, but the volume and quality of data returned from Pluto is so far ahead of the older mission. It just shows what even a single fast flyby of either of the Ice Giants could accomplish with modern instruments.

Phil


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tedstryk
post Jul 15 2018, 12:18 PM
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QUOTE (Phil Stooke @ Jul 15 2018, 05:31 AM) *
I was planning to draw attention to those papers as well. It's true, they are amazing. The thing I keep thinking of is how far ahead we are now compared with Voyager 2's flyby of Neptune and Triton. In some ways the Neptune and Pluto systems are similar (not in sizes but in number of targets) and the fast flybys were similar in timing, but the volume and quality of data returned from Pluto is so far ahead of the older mission. It just shows what even a single fast flyby of either of the Ice Giants could accomplish with modern instruments.

Phil


It's especially evident when you see how many of the Voyager images smeared or missed. Meanwhile, I can't think of an unintentionally smeared New Horizons image (except for the occasional super-long exposure, but even then it's pretty steady).


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