Re: APOD: Unusual Pits Discovered on Pluto (2015 Nov 25)
Posted: Thu Nov 26, 2015 3:39 am
flying thru debris of an ice volcano
APOD and General Astronomy Discussion Forum
https://asterisk.apod.com/
Zounds!! An astounding comparison. Heat below the surface. Investigate Thoroughly!Ozoz1 wrote:Looks like the bubbles an indentations that form when you cook a pancake on a hot griddle...,)
Would be interesting to see a larger portion of the area from a greater distance.SouthEastAsia wrote:My question would be: where is the Sun in relation to this photo? Are there shadows??
Confusing pic nonetheless to me, as there definitely seems to be multiple intricate patterns of various orientations and not some random or singular effect causing these formations.
Ah .. request granted .. and, looks like a little Christian chapel in the top left corner of this image. http://pluto.jhuapl.edu/soc/Pluto-Encou ... _sci_3.jpgAlohascope wrote:Would be interesting to see a larger portion of the area from a greater distance.SouthEastAsia wrote:My question would be: where is the Sun in relation to this photo? Are there shadows??
Confusing pic nonetheless to me, as there definitely seems to be multiple intricate patterns of various orientations and not some random or singular effect causing these formations.
Alohascope wrote:And in the same image notice how the pits seem to conform to the contours of the rugged masses in the lower half of the image .. those masses said in another image to be ice mountains. What happens when ice meets liquid nitrogen? http://pluto.jhuapl.edu/soc/Pluto-Encou ... _sci_3.jpg
Yes, it's a thing. We have a decent understanding of cratering rates for any given body in the Solar System. Cratering on the Moon is actually a tricky issue, because the vast majority of what we see was laid down very early in the history of the Solar System, which hides the much slower rate of cratering that has occurred since.Liebencrantz wrote:There is a lot of intrigue over Plutos apparent lack of meteor impacts which would seem to indicate a relatively active topology. I wonder however if an outer solar system body such as Pluto will have experienced the same rate of impacts as an inner solar system counterpart. Charon certainly displays its battle scars but how does it compare to our weary and loyal Moon?
I ponder to what extent we can use the same timescale to estimate geologic activity based on meteor impact evidence. I'm supposing it would come down to the general distribution of debris in our developing planetary disc determining the probability of pockmarking events. Is this a thing?
I am a zombie, your wish will command me.neufer wrote:...Paralyze the livingstarsurfer wrote:
Pluto continues to astound and surprise everyone holding the world captivated while it whirls its long path around the Sun!
Looking at this picture does funny things to my eyes?!
Just as the Plutonians had planned.
I think the main reason for the lack of impact craters is Pluto's distance away from the asteroid belt and the inner part of the Solar System, which would have contained many meteorites and asteroids in the past.Liebencrantz wrote:There is a lot of intrigue over Plutos apparent lack of meteor impacts which would seem to indicate a relatively active topology.
Perhaps in an absolute sense. But the impact rate is considered in evaluating the age of a surface. The actual crater density on Pluto is indicative of a young surface.starsurfer wrote:I think the main reason for the lack of impact craters is Pluto's distance away from the asteroid belt and the inner part of the Solar System, which would have contained many meteorites and asteroids in the past.Liebencrantz wrote:There is a lot of intrigue over Plutos apparent lack of meteor impacts which would seem to indicate a relatively active topology.
Or maybe it's indicative of an older surface that has been constantly renewed and refreshed with new material that has buried any older impacts?Chris Peterson wrote:Perhaps in an absolute sense. But the impact rate is considered in evaluating the age of a surface. The actual crater density on Pluto is indicative of a young surface.starsurfer wrote:I think the main reason for the lack of impact craters is Pluto's distance away from the asteroid belt and the inner part of the Solar System, which would have contained many meteorites and asteroids in the past.Liebencrantz wrote:There is a lot of intrigue over Plutos apparent lack of meteor impacts which would seem to indicate a relatively active topology.
In planetary science, that's the definition of a young surface. The presumption is that if you don't see the expected cratering, they have been buried or eroded.starsurfer wrote:Or maybe it's indicative of an older surface that has been constantly renewed and refreshed with new material that has buried any older impacts?Chris Peterson wrote:But the impact rate is considered in evaluating the age of a surface. The actual crater density on Pluto is indicative of a young surface.
The pits follow coastlines .. they spread out in refraction wave patterns from those coastlines. A plutoquake could send waves through the ocean, but the quakes would have to be frequent to cause enough waves to melt the ice through the 'heat from beneath' process. Much more likely they are tidal waves caused by the planets interactions with its moons. I use the word planet in the honorable sense.SeedsOfEarth wrote:Could these possibly be the result of a Plutoquake? The most closely aligned pits appear almost like ripples caused by high vibrations (as in water sitting in a cup that ripples when an electric razor is touched to the cup).
Yes mountains. But these mountains do not necessarily penetrate the ice layer. According to my theory, they do not penetrate the ice layer ( so they do not rest on the rocky surface below either).Alohascope wrote: The ice mountains are said to be 10,000 feet high. http://www.space.com/29961-pluto-ice-mo ... hotos.html
Thank you for this MIT link. I can go along with an "ocean" under the ice layer. It is most likely that if there is a liquid ocean, then there is a separation filled with atmospheric gases between the ocean and ice. It could be 100 meters to 1 km or more. So it is not the case that the ice layer would be close enough to the ocean for waves to lick the bottom of it, much less put pressure on it.Alohascope wrote: An ocean of liquid salt water lies under the frozen nitrogen. http://news.mit.edu/2015/new-horizons-d ... ocean-0729
Pluto and Charon constantly present the same face to each other, which is unlike Earth and the Moon. The part of the Earth's surface that faces the Moon changes; thus, the bulge that the Moon causes travels across the surface of the globe along with the Moon. [Refer to the Wikipedia article on "Tide".] This does not happen with Pluto and Charon, and the other moons of Plato are not big enough to cause the effect that you propose.Alohascope wrote: Like earth's moon Pluto's moons cause tides and currents which cause waves in Pluto's ocean.
Those waves move in straight lines and curved lines both towards and out from the ice mountainshttp://www.coastal.udel.edu/ngs/waves.html
I think that your idea here is interesting. So the warmth below the ice layer somehow causes pockets of gas to migrate to the outer surface where it finally escapes into space leaving behind a pock mark. I think we'd have to look at the physics of pancake bubbles to understand whether such a phenomenon could apply to Pluto's ice. Did you know that scientists study gas bubbles in old ice on Earth in order to learn about the ancient atmosphere? So what we are used to is bubbles staying trapped in ice even if warmth is introduced nearby.Alohascope wrote:According to different elevations of rock or whatever lies on the bottom of the saltwater ocean the height of the waves create pressure, more or less, on the bottom surface of the frozen nitrogen. That pressure plus the relative warmth of the salt water creates warmth in the frozen nitrogen, and as in heat from a frying pan heating pancake batter releases bubbles of carbon dioxide, the pits are melted pockets of nitrogen which 'pop' open into pits.
I agree with you, Pianosorplanets, that objects small enough to make craters the size of the pits would just slide off with no impact marks if the surface was fully frozen.Pianosorplanets wrote: I will offer up one speculation. If outgassing of the nitrogen managed to reduce the hard surface these low temperature tend to produce, I suppose it is possible that, as Pluto orbited, an area less firm having been weakened by sublimation crossed a field of objects of unknown size caught in Pluto's way as it made its way around the sun. Like our Leonids as we pass through the bits of Temple/Tuttle but likely considerably larger. That would account for a mass of small, tightly congested craters. But I don't believe this formulation could take place as described unless that lake of harder than rock, frozen nitrogen had sublimated until it had become somewhat fragile first.
My favorite theory of solar-system formation [Mass Vortex Theory] includes a Killer Crash between a recently formed planet Illo and newly-forming planet Smithereens [Smithereens becoming the Asteroid Belt]. I believe that Illo made a glancing blow to one of its moons (Pluto) and deposited some debris during this event. Some small dark rocks from Illo could have scattered over the ice; then the darker albedo of these rocks caused them to heat up and sink, creating the pits. And the splatter from the impact would explain why some of them are more trough-like. The friction from the glancing impact and the impact itself would cause the "fragile" state of the ice according to Pianosorplanets' wisdom.ngc1535 wrote:The pits remind me of snow in grass or small thin plants that stick up. When the sun comes out- each stem develops a pit/hole surrounding it due to slight extra warmth the planet gained from the sunlight due to the difference in albedo (being darker than the snow). So... maybe there are small slightly darker things on the surface that absorb just a bit more feeble sunlight and cause the pits.
The lowest possible speed a body can impact Pluto at is 1200 m/s (and statistically, most impactors will be moving faster than that). Nothing striking at that speed, with that much energy, just "slides off".sallyseaver wrote:I agree with you, Pianosorplanets, that objects small enough to make craters the size of the pits would just slide off with no impact marks if the surface was fully frozen.
Regardless of the details of Solar System formation, the asteroid belt is, without doubt, not the product of collisions. It is extremely well understood in terms of material that failed to coalesce into planets due to orbital resonances with the gas giants. And structurally, the material does not show the kind of shock effects we'd see from a planet-scale collision. And, of course, the entire asteroid belt consists of only a tiny amount of material- no more than a very small planetary satellite.sallyseaver wrote:My favorite theory of solar-system formation [Mass Vortex Theory] includes a Killer Crash between a recently formed planet Illo and newly-forming planet Smithereens [Smithereens becoming the Asteroid Belt].
Point taken. I am interested to knowing why 1200 m/s is the lowest possible impactor speed. Can you fill in the thinking behind this or direct me to a resource?Chris Peterson wrote:The lowest possible speed a body can impact Pluto at is 1200 m/s (and statistically, most impactors will be moving faster than that). Nothing striking at that speed, with that much energy, just "slides off".sallyseaver wrote:I agree with you, Pianosorplanets, that objects small enough to make craters the size of the pits would just slide off with no impact marks if the surface was fully frozen.
Thank you for filling me in on how the Sun-First Theory accounts for the asteroid belt. Coming from a Sun-First point of view, I can see why scientists would think in terms of many collisions, but Mass Vortex Theory posits a single collision as well as a different planet-formation mechanism than Sun-First Theory. Having only a fraction of the original protoplanet's mass near the site of the Crash makes a lot of sense.Chris Peterson wrote:[Regardless of the details of Solar System formation, the asteroid belt is, without doubt, not the product of collisions. It is extremely well understood in terms of material that failed to coalesce into planets due to orbital resonances with the gas giants. And structurally, the material does not show the kind of shock effects we'd see from a planet-scale collision. And, of course, the entire asteroid belt consists of only a tiny amount of material- no more than a very small planetary satellite.sallyseaver wrote:My favorite theory of solar-system formation [Mass Vortex Theory] includes a Killer Crash between a recently formed planet Illo and newly-forming planet Smithereens [Smithereens becoming the Asteroid Belt].
That's the surface escape velocity for Pluto, which is also the speed a body will impact falling freely onto the surface- technically starting at zero speed from an infinite distance, but that's also very close to the minimum speed for any body in solar orbit.sallyseaver wrote:Point taken. I am interested to knowing why 1200 m/s is the lowest possible impactor speed. Can you fill in the thinking behind this or direct me to a resource?Chris Peterson wrote:The lowest possible speed a body can impact Pluto at is 1200 m/s (and statistically, most impactors will be moving faster than that). Nothing striking at that speed, with that much energy, just "slides off".