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

[DavidLeodis]

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

[Beyond]

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.

[Chris Peterson]

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 Peterson]

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.

[neufer]

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.

[Chris Peterson]

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.

[neufer]

It seems reasonable to assume that Pluto's ergs are geological remnants of a past age of denser atmospheres & numerous cryovolcanic eruptions

[b][size=150]Neufer:[/size] [color=#0000FF]The [size=150]relatively recent catastrophic event[/size] that produced crater free Tombaugh Regio could have produced both the cryovulcanism & atmosphere necessary for the downwind ergs of Tartarus Dorsa.[/color][/b]

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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.