APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Comments and questions about the APOD on the main view screen.
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DavidLeodis
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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by DavidLeodis » Sat Sep 26, 2015 1:38 pm

Beyond wrote:The "part" link goes to an MP3 about football players.
I was just about to post about that! I was totally baffled about what it had to do with the image when I have just clicked on that link and an "The Impenetrable Fortress" fantasy league website came up :?

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Beyond
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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by Beyond » Sat Sep 26, 2015 2:00 pm

DavidLeodis wrote:
Beyond wrote:The "part" link goes to an MP3 about football players.
I was just about to post about that! I was totally baffled about what it had to do with the image when I have just clicked on that link and an "The Impenetrable Fortress" fantasy league website came up :?
Thanks David. I didn't realize that was a Fantasy Football link. It must be a professorial phunny. Mythological and Fantasy are very close relatives.
To find the Truth, you must go Beyond.

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Chris Peterson
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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by Chris Peterson » Sat Sep 26, 2015 2:18 pm

OrionEridanus wrote:
Chris Peterson wrote:On the other hand, with such a tenuous atmosphere (which implies very low mass density) you could have winds with incredible speeds- hundreds or even thousands of kilometers per hour. And any "snow" that precipitates is likely to be little more than small clumps of molecules. Under such conditions, I'd be hesitant to say that wind might not be very important in shaping the landscape.
Windspeed cannot exceed the speed of the sound which is solely dependent on temperature and particle mass. If it did the "wind" becomes a shock wave with all the gas piling up on the shock boundary rather than propagating as a pressure driven flow.
That does not argue against high wind speeds. And don't overlook the solar wind, either, which at Pluto has a speed of well over 100 km/s and a temperature of hundreds of thousands kelvin. It probably interacts with the near vacuum of Pluto's atmosphere all the way to the surface.
Chris

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Chris Peterson
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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by Chris Peterson » Sat Sep 26, 2015 2:21 pm

neufer wrote:It seems reasonable to assume that Pluto's ergs are geological remnants of
a past age of denser atmospheres & numerous cryovolcanic eruptions:
I'm not sure that's reasonable. There's a lot of evidence pointing to Pluto having a young surface- far younger than any distant past when the atmosphere was different or the interior more active.
Chris

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neufer
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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by neufer » Sat Sep 26, 2015 2:37 pm

Chris Peterson wrote:
neufer wrote:
It seems reasonable to assume that Pluto's ergs are geological remnants of
a past age of denser atmospheres & numerous cryovolcanic eruptions:
I'm not sure that's reasonable. There's a lot of evidence pointing to Pluto having a young surface- far younger than any distant past when the atmosphere was different or the interior more active.
I never said a "distant" past age.

The young surface does point to a fairly recent past age of geological activity.
Art Neuendorffer

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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by Chris Peterson » Sat Sep 26, 2015 3:12 pm

neufer wrote:
Chris Peterson wrote:
neufer wrote:
It seems reasonable to assume that Pluto's ergs are geological remnants of
a past age of denser atmospheres & numerous cryovolcanic eruptions:
I'm not sure that's reasonable. There's a lot of evidence pointing to Pluto having a young surface- far younger than any distant past when the atmosphere was different or the interior more active.
I never said a "distant" past age.
A denser atmosphere certainly requires an extremely distant (possibly infinitely distant) past.
Chris

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Re: APOD: Pluto's Snakeskin Terrain (2015 Sep 25)

Post by neufer » Sun Sep 27, 2015 12:46 pm

neufer wrote:
It seems reasonable to assume that Pluto's ergs are geological remnants of a past age of denser atmospheres & numerous cryovolcanic eruptions
Chris Peterson wrote:
neufer wrote:
Chris Peterson wrote:
There's a lot of evidence pointing to Pluto having a young surface- far younger than any distant past when the atmosphere was different or the interior more active.
I never said a "distant" past age.
A denser atmosphere certainly requires an extremely distant (possibly infinitely distant) past.
Art Neuendorffer