Those Dark Spots on Pluto

The latest high definition image is a little worrying...

http://imgick.silive.com/home/silive-media/width620/img/latest_news/photo/pluto-death-starjpg-0912af5ea77e42c3.jpg

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@Brandon9000,

Brandon9000 wrote:

As far as I know, gas condensed to form the planets and moons, except for our Moon, which was formed by a collision.

My understanding was that planets (and planetesimals) formed from a wide range of stellar "debris" orbiting the young star. This would include a full range of gas, dust, grit, pebbles, rocks, boulders, and bigger and bigger chunks of "stuff". However, I have never understood what proportion the various chunks of stuff arrived in. If it's 99% dust then I'm not surprised if smaller bodies form spherical objects. But if it's 99% asteroid sized chunks, then I would expect to see the objects with lower gravitation look very uneven.

Pluto seems to be very spherical including surface formations indicating some type of geologic activity. I'm just a bit surprised given its surface gravity is 0.063g (compared to 1g for Earth).

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@rosborne979,

rosborne979 wrote:

Brandon9000 wrote:
As far as I know, gas condensed to form the planets and moons, except for our Moon, which was formed by a collision.

My understanding was that planets (and planetesimals) formed from a wide range of stellar "debris" orbiting the young star. This would include a full range of gas, dust, grit, pebbles, rocks, boulders, and bigger and bigger chunks of "stuff". However, I have never understood what proportion the various chunks of stuff arrived in. If it's 99% dust then I'm not surprised if smaller bodies form spherical objects. But if it's 99% asteroid sized chunks, then I would expect to see the objects with lower gravitation look very uneven.

Pluto seems to be very spherical including surface formations indicating some type of geologic activity. I'm just a bit surprised given its surface gravity is 0.063g (compared to 1g for Earth).

I haven't read Setanta's article on planetesimals yet, but my understanding has always been that it's usually just gas that starts forming clumps because of the action of gravity. There is a lot of gas in the universe - more, I should think, than chunks of rock.

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Straw man much? Who said anything about "chunks of rock?" I thought you were supposed to be one of the science boys.

From Britannica's science section, the definition of accretion disk:

Quote:

Accretion disk, a disklike flow of gas, plasma, dust, or particles around any astronomical object in which the material orbiting in the gravitational field of the object loses energy and angular momentum as it slowly spirals inward. In astrophysics, the term accretion refers to the growth in mass of any celestial object due to its gravitational attraction. The formation of stars and planets and the powerful emissions from quasars, radio galaxies, X-ray binaries (see X-ray astronomy), and probably also Type Ia supernovas all involve accretion disks. The astronomical object whose mass is growing is known as the accretor.

The planetesimal "theory" (hypothesis would be a more accurate term) holds that larger and larger bodies form from the matter in the accretion disk, and that that is how bodies such as planets and their satellites form. The concept is, of course, far more complex than that--that's just a simple statement which does not take into account varying orbital paths with regard to the star (for example, Mars' orbit is far more elliptical than that of Terra--our earth), nor the effects of collisions, such as the planetesimal collision which is hypothesized to have created "the moon" of Terra.

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@Setanta,

Brandon9000 wrote:

...There is a lot of gas in the universe - more, I should think, than chunks of rock.

Setanta wrote:

Straw man much? Who said anything about "chunks of rock?" I thought you were supposed to be one of the science boys....

I was answering this statement by rosborne979:

rosborne979 wrote:

...formed from a wide range of stellar "debris"...pebbles, rocks, boulders, and bigger and bigger chunks of "stuff"...

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You might benefit more from reading this Harvard Astronomy 201B page.

https://ay201b.files.wordpress.com/2011/04/proplyd_concept.jpg

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@Brandon9000,

Actually, Roswell wrote:

". . . dust, grit, pebbles, rocks, boulders, and bigger and bigger chunks of "stuff"."

. . . suggesting an ongoing process of accretion and not that there were "chunks of rock" ubiquitous in the cosmos.

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@edgarblythe,

Amazing stuff.

I wonder how long it'll be before Gunga sees a pyramid up there Wink

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You didn't see those square plots on the upper right-hand side? Are you blind?

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@rosborne979,

The Tombaugh Regio area is an area under analysis right now. I was talking with a colleague down at the geo dept at the "Hop" and in this area are what Id caalled "patterned ground" very similr to the polygonal structures in the perma frost swampy zones of Alska . Perhaps this is an area where the liquid phases of a nitrogen or methanyl gas acts just like water on this planet nd forms these ptterned ground features where we see prtial melt and ice heaving.

Its really interesting to envision that this plnet has an ctive tectonic platform because now they hve to think up a mechanism.

There was a theory that Marshall Kay came up with back in the late 60's (just before Seafloor spreading and continental drift became household words .) KAY called it "continental Drip", and it was a low energy sort of spreading that was induced by plastic "strut" layers where firm rocklike layers (un hardened at that point) would slide over clay rich deposits of sement clled "flysch".
Kay presented continentl drip s a hlf ass ttempt at humor but we may hve to think about some ressurection when a naturl "dynamo" earth nd aa plstic/liquid mantle doesnt exist.

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@farmerman,

If the planet is covered with frozen water, it does raise the question of how ice acts differently than rock or if it would be similar under those conditions. Certainly you don't need as warm a temperature inside the planet to turn the bottom of those ice oceans to water allowing movement of the ice above.

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@parados,

"Ice" is a term we usually reserve for frozen water , but we do have several other ices like "dry ice" "methane ice" (or methyl clathrate or methane hydrate), or "ammonia Ice" which gets to be a solid at -110F.
So ices may actually be something else other than water.

The huge slide blocks of the NC Blue Ridge mountains have clear evidence showing that the Pine Mountain Thrust is a block of "slippery" shale that underlies flat block of sand stone (bout 100 miles by 60 miles). The shale, " a slippery strut formation" acted like a water slide and carried the slab of sandstone at a very low angle (just a few degrees off horizontal) for about 75 miles.
This kind of tectonic could be in action on Pluto too. Not all tectonics must be linked to the mantle by convection.
Think how the glaciers pounded the Canadin Shield to a fairly flattened state

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@rosborne979,

rosborne979 wrote:

Brandon9000 wrote:
As far as I know, gas condensed to form the planets and moons, except for our Moon, which was formed by a collision.

My understanding was that planets (and planetesimals) formed from a wide range of stellar "debris" orbiting the young star. This would include a full range of gas, dust, grit, pebbles, rocks, boulders, and bigger and bigger chunks of "stuff". However, I have never understood what proportion the various chunks of stuff arrived in. If it's 99% dust then I'm not surprised if smaller bodies form spherical objects. But if it's 99% asteroid sized chunks, then I would expect to see the objects with lower gravitation look very uneven.

Pluto seems to be very spherical including surface formations indicating some type of geologic activity. I'm just a bit surprised given its surface gravity is 0.063g (compared to 1g for Earth).

You have to consider the formation process. It has been suggested that planets, moons and dwarf planets are mostly round in shape because they developed early which means they had a lot of asteroid bombardments which created a molten surface due to high energy impacts.

A planet is really just like a bubble, so when you have a molten core and surface it will naturally result in a more roundish shape. Mountains usually form just as the planet/moon/dwarf planet is cooling. Where parts of the surface are still molten and other parts have solidified and cooled. There is natural movement which causes uprising to occur. Chunks float on the molten surface and bump into each other forcing pieces up which then cool in place.

Once the entire surface cools these uplifts are left behind to form mountains. When there is little to no atmosphere these mountains will not erode away like they do on Earth. The reason the Earth has mountains still is because we have a molten core which causes the plates to bump into each other causing uplifting.

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Probe suspected of playing Crash Bandicoot to pass time during 9-year journey.
PETER DOCKRILL17 JUL 2015
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New Horizon’s 9-year voyage across the Solar System to Pluto and beyond is the stuff scientific dreams are made of. But one of the most remarkable tidbits at the heart of NASA’s history-making endeavour is that the probe accomplished its epic feat with only a PlayStation 1 processor for a brain.

As pointed out by Alexandru Voica at tech blog Imagination, the same MIPS R3000 processor used to control New Horizon’s onboard systems once powered the first generation of Sony’s popular gaming console, which hit the market more than 20 years ago.

According to Voica, the MIPS R3000 CPU goes back even further than that – it was first used in workstations and servers as far back as the late 1980s. The chip on board New Horizon is a special, radiation-hardened version of the CPU, but its computational capabilities are only as powerful as the gaming console you used to play Tomb Raider on, back when Lara Croft was all chunky and polygonal. (Though still rather fetching, admittedly.)

James Vincent at The Verge says, “This isn’t unusual behaviour for NASA though, as the space agency always prefers the tried-and-tested to the cutting-edge. The next-generation Orion spacecraft, for example - the one that will hopefully take humans to Mars one day - is controlled by an IBM processor made back in 2002.”

It’s not the first time PlayStations have been used for ground-breaking scientific research, but still, we have to admit we’re blown away at what the humble PS1’s CPU has been able to achieve. MIPS R3000, we thank you for your ongoing service to humankind!

In fact, it may even go as far as to justify some of the more grandiose claims of the console’s ’90s heyday advertising…
http://www.sciencealert.com/nasa-s-new-horizon-probe-made-it-to-pluto-with-a-playstation-cpu-for-a-brain

1 Reply

@edgarblythe,

An interesting thought overall. Imagine we send a manned mission to Alpha Centauri knowing itll take many years (hundreds actually). But then,what if, 100 years into the mission we invent a new power source that allows us to accelerate to 90% c. That would speed up the whole trip to, say, 4.8 years one way. What do we do with the poor schlubs whose entire life spans have been devoted to a mission that was expected to take 250 years and now can be done like a tour on a present day naval vessel.

I think this requires an entirely new space paradigm.
1. Should a mission expend time measured in multiple life times, we only send initial missions with robotics until a "futurist analysis" can more accurately predict what increased V of the missions space vehicles would actually be in say, 50 to 100 years. (Sort of like Moores Law with life time implications)

2. I think our overall "manned" programs for exploration or colonization for anything over , say 20% pf a light year be purposely held up until our ship velocities can be predicted to be well beyond that distance barrier (up to, about 85 to 90% c.

3 I think we will soon be calculating missions based upon% c.(9 years to an otherwise unimportant destination like Pluto, sends a message that any missions beyond Kuiper belt have multigenerational implications and mission vehicles and gear will be obsolete long before the mission is complete

I know its bullshit but at least it is something to shoot at, its sort of a time dependent "mission life envelope"

Weve increased sizes of our rockets and hve miniteurized electronics so much that we are now able to make space for humans to be rather comfortable while they travel. Yet we havent really been able to increase our ship velocities by any appreciable amount.Were still in the miles per hour realm. We are in the sailing ships age of space travel

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I didn't notice impact craters on Pluto.

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@edgarblythe,

edgarblythe wrote:

I didn't notice impact craters on Pluto.

That seems to be one of the big surprises from the flyby.

The surface is either geologically active, or covered in something thick enough to cover craters, or there weren't as many impacts since the surface cooled/hardened.

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Think "splosh craters"--if Pluto is sitll "geologically" active, a splosh crater would be cleared up pretty quickly.

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Another consideration is that in an accretion disk, object tend to "fall" toward the center of gravity--i.e., the sun. There may never have been that man meteors in that neighborhood to begin with.

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Those Dark Spots on Pluto

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