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

[APOD Robot]

Pluto's Snakeskin Terrain

Explanation: A mountainous region informally known as Tartarus Dorsa sprawls some 530 kilometers (330 miles) across this Plutonian landscape. Recently downloaded from New Horizons, it combines blue, red, and infrared image data in an extended color view captured near the spacecraft's close approach to Pluto on July 14. Shadows near the terminator, the line between Pluto's dim day and night, emphasize a rough, scaly texture. The stunning image resolves details on the distant world about 1.3 kilometers (0.8 miles) across. Refering to a part of Hades in ancient Greek mythology, Tartarus Dorsa borders Tombaugh Regio to the east.

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[Beyond]

The "part" link goes to an MP3 about football players.

[Boomer12k]

A very intriguing place....rumples, gouges, dimples...etc...and to the right, what would appear to be LAKES, if there was water there...like the Mare on the Moon...

Awesome looking....

:---[===] *

[azman45]

One the lower right side of the picture there appears to be flattened areas on top of the ridges. It shows almost as if a large rasp or file worked them down to a perfectly flat area. I wonder if that is an anomaly of the photo or actual.

[stolenmoment]

The area at the right edge looks more like a layer of fluff blown across a much flatter surface.

Also, look at the various ages of the craters! A small number look new (sharp), others (like the one near center, retaining a bit of central peak) look very eroded, like there was some resurfacing event that created this mess, fairly recently.

I can't wait to hear what the geographers (plutographers?) have to say about it.

[APODFORIST]

This is an amazing and superb picture.

Pluto for Planet!

My first thought: Could it show the lakes on Titan? But this never seen picture had come too late from this old Saturn mission.

[neufer]

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[b][color=#0000FF][size=125]Astronaut photograph ISS013-E-65526 was acquired August 8, 2006, with a Kodak 760C digital camera with an 800 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center. The image in this article has been cropped and enhanced to improve contrast.[/size][/color][/b]

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Dune Types in the Issaouane Erg, Eastern Algeria
Earth Observatory, September 11, 2006

<<This view from one of the smaller dune seas in the central Sahara Desert shows the complex but regular patterns produced in deserts where wind and sand both abound. The image is centered at 26.9 North, 7.4 East, over eastern Algeria. Geologists now know that dune seas (also called ergs) exhibit at least three orders of dune size. The biggest dunes, called mega-dunes, probably took hundreds of thousands of years to accumulate, starting when the Sahara began turning arid roughly 2.5 million years ago. Rivers became smaller, failed to reach the sea, and deposited their sand load in the desert. Wind did the rest, blowing the sand into aerodynamic dune forms. Superimposed on the mega-dunes are mesoscale dunes (the prefix meso- means “intermediate.”) Whereas the mega-dunes are apparently stationary, studies based on aerial photographs in other parts of the world show that mesoscale dune crests move in the course of decades. The smallest dunes form and reform the fastest, meandering over the backs of the larger dunes.

In this image, the mega-dunes appear as big, rolling lumps that zigzag toward the upper right. The “streets” between these biggest dune chains have been swept clean of sand in places, showing their original surfaces of pale mud and salts. The pale beige-grey of these areas contrasts with the otherwise burnt orange hues. Mesoscale dunes, some of which form octopus-like crests, or star dunes, mark the backs of the mega-dunes. The smallest dunes appear in patches on the eastern sides of the mega-dunes as a tracery of closely spaced crests. Interestingly, the crest orientation of the small dunes differs from the orientation of the mesoscale dunes. This difference is a common effect of local shifts in wind direction, which is influenced by dune height.

The orientation trends in the mega-dunes coincide with two of the four major trends identified in the Great Eastern Sand Sea (or Grand Erg Oriental) immediately to the north. Each orientation shift likely implies a shift in the direction of the dominant wind that formed the dunes, attesting to the climate shifts that have occurred since sand began to accumulate in the central Sahara.>>

[MadMan]

The area at the right edge looks more like a layer of fluff blown across a much flatter surface.

That's what I was thinking - like a mass of molten rock splashed from left to right, and then froze before it had a chance to level out.

[gwhastings]

Snow drifting on Earth often begins at relatively low wind speeds, from about 4 m/s.
If Nitrogen, Carbon Monoxide, and Methane sublimate during solar periapsis, then cools and precipitates as Pluto's orbital distance from the sun increases, it could be possible for these frozen gases to fall to the surface as light, powdery crystals that could be shifted into massive drifts with the appearance of this "snakeskin terrain" by the thin atmospheric winds that may blow across the surface of Pluto.
https://www.flickr.com/photos/captgeorg ... ed-public/

[Ron-Astro Pharmacist]

The shadows cast onto the smooth plains in this image do provide an invocative view but inferring knowledge from a low angle perspective is difficult to interpret. Art or science?

[captainwiggins48]

The seemingly sculpted landscape of Pluto may have been caused by past supernova events of nearby stars, and/or events from our own sun, all nicely preserved for us to ponder.

[MarkBour]

When the caption says: "resolves details on the distant world about 1.3 kilometers (0.8 miles) across.", is this a subjective statement, or can it be translated into something more specific, such as "each pixel is 1.3 km"? I'd be interested in knowing that. It would be helpful for the scale to compare this image to a shot of some of the worst badlands on Earth at the same scale. At the scale these may be, and with the likelihood that the atmosphere of Pluto has always been super-thin, I am doubtful that wind played much of a role in forming these structures.

[neufer]

The seemingly sculpted landscape of Pluto may have been caused by past supernova events
of nearby stars, and/or events from our own sun, all nicely preserved for us to ponder.

The Sun has an apparent magnitude of −19.4 for Pluto at aphelion.

This is almost exactly the absolute magnitude of a supernova.

Hence, a supernova would have to take place much much closer than the standard
distance of 10.0 parsecs to have a significant heating effect upon Pluto.

[Chris Peterson]

When the caption says: "resolves details on the distant world about 1.3 kilometers (0.8 miles) across.", is this a subjective statement, or can it be translated into something more specific, such as "each pixel is 1.3 km"?

I'm sure it's a rigorous value, based on the actual pixel resolution. But whether it's the actual pixel scale, or something derived from it (for instance, you could say that you need two pixels to define actual resolution), I don't know. But the camera has a resolution of 1 arcsecond per pixel, so you can work out the resolution any way you like if you know the distance from Pluto where the image was made.

At the scale these may be, and with the likelihood that the atmosphere of Pluto has always been super-thin, I am doubtful that wind played much of a role in forming these structures.

You might think. 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.

[Ron-Astro Pharmacist]

Lots of information coming available reported from a variety of sources.

http://www.ibtimes.com/plutos-scaly-sna ... ns-2113819

Pluto must be good for business.

[Asterhole]

One sees those ridges and may immediately think "dunes!" but it may be far from reality. There could be many other forces other than aeolian at work here. One thing is certain - that surface is cosmically young, being less than a billion years old. And it may still be active. It is suspected by the New Horizon team that Pluto's surface consists of frozen gases along with water ice. With the close proximity of Charon in orbit, thermic reactions could be occurring within Pluto's subsurface, maybe just below the surface which are sculpting the landforms we see.

We shall wait and see what the New Horizons team comes up with.

[neufer]

When the caption says: "resolves details on the distant world about 1.3 kilometers (0.8 miles) across.", is this a subjective statement, or can it be translated into something more specific, such as "each pixel is 1.3 km"? I'd be interested in knowing that.

Lose yourself in this high-resolution portrait of Pluto
Posted By Emily Lakdawalla

<<[New Horizons team member Alex Parker] confirmed that the image had been upsampled (enlarged) by a factor of 2 as a part of his deconvolution process. I'm oversimplifying here, but deconvolution is a step in image processing where you account for the fact that your detector has an inherent blur. Before you send a scientific camera to space, you perform a lot of tests on it to understand very precisely the geometry of that blur. With an excellent model of its geometry, you can take the blur out, sharpening the images in a way that is very specific to your precise understanding of your scientific camera.>>

<<It would be helpful for the scale to compare this image to a shot of some of the worst badlands on Earth at the same scale. At the scale these may be, and with the likelihood that the atmosphere of Pluto has always been super-thin, I am doubtful that wind played much of a role in forming these structures.>>

I wouldn't second guess any atmosphere that can maintain a dozen haze layers.

The real issue is not how wide these "dunes" are but rather how high (and of what the are made).

[ta152h0]

when is Sky and Telescope put this stuff in print ?

[ta152h0]

So on Pluto they be called " dwarf ergs " ?

[Ron-Astro Pharmacist]

When the caption says: "resolves details on the distant world about 1.3 kilometers (0.8 miles) across.", is this a subjective statement, or can it be translated into something more specific, such as "each pixel is 1.3 km"? I'd be interested in knowing that. It would be helpful for the scale to compare this image to a shot of some of the worst badlands on Earth at the same scale. At the scale these may be, and with the likelihood that the atmosphere of Pluto has always been super-thin, I am doubtful that wind played much of a role in forming these structures.

I don't know what a "shot of the worst badlands on Earth" would look like but here's one of the "best" Badlands. Quite a place!

They may even have some similarities to today's APOD. Though not the same scale our car was doing a fly-by.

[neufer]

[b][color=#0000FF]Treeships are living trees that are propelled through space by ergs (spider-like solid-state alien beings that emit force fields).[/color][/b]

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So on Pluto they be called " dwarf ergs " ?

<<An erg is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The term takes its name from the Arabic word ʿarq (عرق), meaning "dune field". Strictly speaking, an erg is defined as a desert area that contains more than 125 square kilometres of aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara, covers 9 million square kilometres and contains several ergs. Ergs are also found on other celestial bodies, such as Venus, Mars, and Saturn's moon Titan.>>

<<The Hyperion Cantos is a series of science fiction novels by Dan Simmons. Much of the action in the series takes place on the planet Hyperion. It is described as having one-fifth less gravity than Earth[; Pluto has 1/16 g]. Hyperion has a number of peculiar indigenous flora and fauna, notably Tesla trees, which are essentially large electricity-spewing trees.

Hyperion is also a "labyrinthine" planet, which means that it is home to ancient subterranean labyrinths of unknown purpose. Most importantly, Hyperion is the location of the Time Tombs, large artifacts surrounded by "anti-entropic" fields that allow them to move backward through time.>>

[Pluto hugger]

Looks pretty nasty as a picnic spot - Ctulhu and Hades indeed. Apart from that, all these sharp edges are reminiscent of comet 67P and, yes, Hyperion. Plenty of sublimation going on there.

[OrionEridanus]

. 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.

[OrionEridanus]

Spectacular.

There does appear some color band mis-registration at the sub-pixel level giving the image a sort of blurry appearance.

[neufer]

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.

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

[b][color=#0000FF][size=125]Dark streaks across Triton's south polar cap surface, thought to be dust deposits left by eruptions of nitrogen geysers[/size][/color][/b]

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<<Triton is geologically active; its surface is young and has relatively few impact craters. Although Triton is made of various ices, its subsurface processes are similar to those that produce volcanoes and rift valleys on Earth, but with water and ammonia lavas as opposed to liquid rock. Triton's entire surface is cut by complex valleys and ridges, probably the result of tectonics and icy volcanism. The vast majority of surface features on Triton are endogenic—the result of internal geological processes rather than external processes such as impacts. Most are volcanic and extrusive in nature, rather than tectonic.

The Voyager 2 probe observed a handful of geyser-like eruptions of invisible nitrogen gas and entrained dust from beneath the surface of Triton in plumes up to 8 km high. Triton is thus, along with Earth, Io, and Enceladus, one of the few bodies in the Solar System on which active eruptions of some sort have been observed.

All the geysers observed were located between 50° and 57°S, the part of Triton's surface close to the subsolar point. This indicates that solar heating, although very weak at Triton's great distance from the Sun, plays a crucial role. It is thought that the surface of Triton probably consists of a translucent layer of frozen nitrogen overlying a darker substrate, which creates a kind of "solid greenhouse effect". Solar radiation passes through the surface ice, slowly heating and vaporizing subsurface nitrogen until enough gas pressure accumulates for it to erupt through the crust. A temperature increase of just 4 K above the ambient surface temperature of 37 K could drive eruptions to the heights observed. Although commonly termed "cryovolcanic", this nitrogen plume activity is distinct from Triton's larger scale cryovolcanic eruptions, as well as volcanic processes on other worlds, which are powered by the internal heat of the body in question. Analogous CO2 geysers on Mars are thought to erupt from its south polar cap each spring.

Each eruption of a Triton geyser may last up to a year, driven by the sublimation of about 100 million cubic metres of nitrogen ice over this interval; dust entrained may be deposited up to 150 km downwind in visible streaks, and perhaps much farther in more diffuse deposits. Voyager 2‍‍ '​‍s images of Triton's southern hemisphere show many such streaks of dark material. Between 1977 and the Voyager 2 flyby in 1989, Triton shifted from a reddish colour, similar to Pluto, to a far paler hue, suggesting that lighter nitrogen frosts had covered older reddish material. The eruption of volatiles from Triton's equator and their deposition at the poles may redistribute enough mass over the course of 10,000 years to cause polar wander.>>