November 17th, 2018
Space Rocks and Pluto Rules
The solar system is assumed to be made mostly from the same stuff throughout, this is why studying the Earth, meteorites, asteroids and comets can help us understand how solar system bodies form. The primary variance in solar system bodies tends to develop from variations in temperature.
Variations in temperature develop from several factors but all are the result of induced energy whether from the Sun, planetary resonant pulses, planetary flex from eccentric orbits, impacts, radioactive decay or chemical interactions. Objects further from the Sun receive less radiative heat energy but also receive less energy from impacts since orbital velocities are significantly slower, in addition, distances between outer solar system bodies are much increased, thereby, reducing impact frequency.
Variations in temperature develop from several factors but all are the result of induced energy whether from the Sun, planetary resonant pulses, planetary flex from eccentric orbits, impacts, radioactive decay or chemical interactions. Objects further from the Sun receive less radiative heat energy but also receive less energy from impacts since orbital velocities are significantly slower, in addition, distances between outer solar system bodies are much increased, thereby, reducing impact frequency.
As we migrate further away from the Sun temperature drops and volatile ices tend to dominate the bodies of the solar system. |
Near the Sun (less than 2 AU) where the terrestrial rocky planets reside, most of the volatile gasses (ices) are evaporated away into space, hence, we are left with an abundance of the harder metals and minerals with a relatively few of the more volatile gasses. 
|
|
Earth Rocks come in three flavors
Melting points of Rock and metal
If you melt sand or silica dioxide (SiO2) and cool it rapidly such that it does not have time to form a crystal lattice structure, it becomes an amorphous glass such as obsidian or olivine. Olivine is a SiO2 rock/glass that is green but some sands are silica rock/glass that is reddish/yellow/brown. Obsidian is typically a black silica glass mixed with magnesium and/or iron. |
Granite
Black & white volcanic obsidian
|
Red, Brown, White, Black, Green, Yellow silicate glass
|
Obsidian arrow heads
|
|
|
|
>>>>>>>>>>>>>>>>>>>>> In this image take note of how the asthenosphere is referred to as "plastic" (flexible, pliable), whereas, the mantle is "stiffer" Felsic or Feldspar rocks are constructed primarily of lighter materials such as silica, sodium and potassium (sandy quartz) and are less dense (2.56 g/cm^3) than rocks that are more magnesium and iron rich. Granite is a felsic rock. Felsic rock makes up about 41% of the stuff you walk on, on Earth. Wiki Quote Feldspars (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8) are a group of rock-forming tectosilicate minerals that make up about 41% of the Earth's continental crust by weight. Feldspars crystallize from magma as veins in both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. As we migrate deeper into the Earth's core;
While this pattern exists on rocky bodies like asteroids and dwarf rocky planets, it does not necessarily hold true for ice dominant bodies like comet 67P. Water has a density of 1 g/cm^3, ice has a density of 0.916 and Comet 67P has a density of only 0.533. Its core has been compared to cotton candy. |
Earth Science Reference Table (ESRT)
|
|
This is a commonly expressed unreasonable explanation describing the Earth's core where crustal rigid rock migrates down through the mantle, heats then rises again in a process called convection.
>>>>>>> Since colder fluids are more dense than warmer fluids it is depicted that the upper crystallized crust subducts down through the mantle dropping as a cold slab of rock falling through denser lava. The problem with this scenario is that the less dense rock is a brittle crystalline (conductive) material that resides at the upper crust boundary of the lithosphere and is less dense than the material below. Less dense crystallized conductive material does not sink down into more dense material just because its in a more fluid state. Density increases toward the core. Density defines the layers and because of pressure the mantle is stiffer than the plastic athenosphere |
|
|
While this concept of convection currents apply to liquids of similar densities since temperature dictates density in fluids, it doesn't apply to solids as they are conductive in nature (they don't easily transfer heat).
A less dense solid rigid crust might possibly get pushed down via subduction to a small degree, however, it would quickly fracture and break at some point and remain at its upper less dense zone. This less dense iron anvil (7.874 g/cm^3) getting pushed down into a bath of more dense liquid mercury (13.534 g/cm^3) serves as an example. >>>>>>>>>>> |
|
Meteorites
|
Meteorite types & ratios found on Earth
Stone 94% (silicate/magnesium oxide minerals).
Metal 5% (Iron/nickel) melted metals must have formed under heat and pressure inside a large bodied asteroid which was sometime later broken apart by an impact. |
|
Stony/Metal mix 1% (Called Pallasite) The metal portion of pallasite is melted around silicate rocks.
Pallasite meteorites are roughly 50% stone and 50% iron (differentiated). Stony/metal meteorites are achondritic crystallized silica stone that have a much higher melting point than iron housed inside a melted iron metal cocoon.
Pallasite meteorites are roughly 50% stone and 50% iron (differentiated). Stony/metal meteorites are achondritic crystallized silica stone that have a much higher melting point than iron housed inside a melted iron metal cocoon.
|
Two hundred and forty one meteorites were studied to understand the average ratio of each compound found inside. Knowing this gives a rough sense of what ratios of matter are floating around the solar system and subsequently the general ratios and compositions of larger potentially planetary bodies.
The suffix meaning of pallasite, meteorite, granite or chondrite in French is ite or Latin ita or Greek ites "connected with or belonging to" = ite When two or more basic elements are combined or bonded together, they are a compound.
|
|
|
Meteorite Composition ratios
The most abundant compounds inside meteorites are
A rare Pallasite meteorite named Fukang (once an asteroid)
>>>>>>>>> Boundary Conditions: We observed multiple (olivine) inclusions hundreds of microns in length in Fukang. These inclusions contain a Cr-rich silicate (Cr=chromium), silica crystals, and k-rich (k=potassium) orthoclase-normative glass. We identified the silica crystals as monoclinic tridymite. The presence of tridymite provides a constraint on the size of the pallasite parent body since tridymite is a SiO2 polymorph that only crystallizes in a narrow range of pressures (<0.40 GPa) and temperatures (870–1470 °C). The pressure stability for tridymite varies in the literature (0.15 – 0.40 GPa) due to the presence of impurities that catalyze its formation. Pallasite is a metal/rock meteorite with olivine crystals encased in melted iron which means these types of meteorites formed between temperatures of 1,536 °C (greater than iron’s melting point) & 1,900 °C (less than olivine’s melting point). The presence of tridymite in Fukang further narrows the melting temperature and pressure under which it developed. The temperature of normal mafic (magnesium – ferric (iron)) or surface ejected basaltic lava on Earth is 700 to 1,200 °C (too cool to melt iron and form a pallasite meteorite). Jupiter’s moon Io on the other hand expels ultramafic lava which is 1,700 to 2,000 °C. Pallasite meteorites could potentially exist at Io surface conditions but for inclusions of tridymite to form, a pallasite meteorite needs specific temperature AND pressure conditions, hence, a meteorite like Fukang had to form deep inside its parent body. The temperature and pressure range for producing pallasite meteorites with tridymites presents a somewhat singular scenario for its development. Most scientists for the past 30 years have felt the asteroid belt is leftover material from the solar system's formation which never successfully came together as one planet. But recent scientific studies demonstrate this is not the case and tridymite in pallasite meteorites is simply more corroborating evidence of this fact. |
Fukang a rare pallasite (melted iron infused with olivine) meteorite
Tridymite
|
The below image shows how close the temperature was to iron's melting/non-melting point as some sections of the pallasite's iron are globular while other areas are crystallized cooling at different rates. Slow cooling allow atoms to align in a structural lattice before they harden and lock into place.
The olivine looks like it barely heated as it's constituent parts are clearly separated into distinct banded lines. This section of pallasite was formed very near the coolest temperatures and pressures possible.
The olivine looks like it barely heated as it's constituent parts are clearly separated into distinct banded lines. This section of pallasite was formed very near the coolest temperatures and pressures possible.
The fact, pallasite meteorites exist demonstrate how some of these inner solar system asteroid bodies have been altered away from their original form. Finding less altered solar system objects requires migrating further away from the Sun.
HED Meteorites
|
Wiki says
HED meteorites are all thought to have originated from the crust of the asteroid Vesta, their differences being due to different geologic histories of the parent rock. Their crystallization ages have been determined to be between 4.43 and 4.55 billion years from radioisotope ratios. HED meteorites are differentiated meteorites, which were created by igneous processes in the crust of their parent asteroid. HED meteorites are a subgroup of achondrite meteorites. Sixty percent of achondrite meteorites are HED. They were formed under igneous (magma or lava) conditions HED is an acronym of Howardite, Eucrite and Diogenite type meteorites
|
|
An additional interesting aspect of Vesta are its equatorial strata bands. These bands show obvious signs of pit chains indicating these are subsurface slip fault features. Page 102 explains slip fault pit chains in more detail. These slip fault pit chains indicate a cooling contraction process took place on Vesta.
|
Riedite
Quote Hypervelocity impact processes are uniquely capable of generating shock metamorphism, which causes mineralogical transformations and deformation that register pressure and temperature conditions far beyond even the most extreme conditions created by terrestrial tectonics. The mineral zircon (ZrSiO4) responds to shock deformation in various ways, including crystal-plasticity, twinning, polymorphism (e.g., transformation to the isochemical mineral reidite) Reidite is a very rare altered zircon mineral formed under extreme pressure and temperature induced by impact shock waves, the same kind of impact shock waves that form Howardite. |
|
The samples of HED meteorites along with pallasite meteorites tell us conclusively that some bodies in the main asteroid belt grew large enough to differentiate into various layers through increasing geological pressure, temperature and density then some time later, that same body was catastrophically shattered.
Asteroids
Eighty six percent of asteroids are chondrites formed from rubble piles similar to what we see taking place on Ryugu and Bennu.
Japan sent a probe to Ryugu to gently touch down and collect a sample which will be returned to Earth in 2020. NASA is preparing to do the same thing on asteroid Bennu.
Close up images show how amazing these objects are but to give a sense of scale, I've added this below image of Vesta with other asteroids and their relative sizes.
Close up images show how amazing these objects are but to give a sense of scale, I've added this below image of Vesta with other asteroids and their relative sizes.
|
Ryugu is larger than Itokawa >>>>>>>
Its close to the size of Annefrank <<<<<<<< but the really cool thing is, Japan landed a probe on Ryugu. |
|
|
One astronomical unit (AU) is the distance from Earth to the Sun and is used as a simple solar system measurement standard. Mars' is about 1.5 AU from the Sun. Apollo asteroids are a group of Near Earth Objects (NEO) that orbit closer to the Sun than Mars (less than 1.1 AU) and could potentially impact with Earth some day but not anytime soon. Ryugu is a NEO Apollo asteroid. Apollo asteroids cross the orbital path of Earth. Asteroids in the main asteroid belt are beyond Mars' orbital path (2-3.5 AU). Within the asteroid belt, there is a zone where objects transition from rocky silicate magnesium oxide dominant bodies to organic carbon based water ice rich bodies. This zone is called the frost line because the Sun's radiative energy is too weak to evaporate water ices as the temperature drops. Beyond the frost line, bodies tend to be more ice rich, at least from a volume standpoint. |
Ryugu and Bennu are considered part of the Polana family of main belt asteroids. Below, the Polana family are the red dots.
|
The asteroid belt, long purported to be just a jumbled hodge podge of rocks orbiting between Mars and Jupiter is now known to be a family of objects from 5 or 6 previous larger bodies.
In other words, there used to be basically 6 large bodies smaller than Mars which were driven to collision and self-destruction. We partially know this because meteorites like Fukang could only develop inside a body with specific pressure and heat conditions. It is also known by their spectrographic similarity and orbital resonance, inclination and eccentricity that these groups of objects once belonged together. |
|
The biggest difference between Bennu and Ryugu has to do with water. Even though scientists believe them to be portions of the same parent body, which broke apart between 800 million and one billion years ago, Bennu appears to be water rich, while Ryugu is less so. The same holds true for the near Earth Apollo objects Encke and 2004 TG10 which are part of the Taurid meteor shower which occurs twice per year (June & Nov). Encke is considered a comet while 2004 TG10 is an asteroid yet both come from the same astronomical object which is thought to have begun breaking up 20,000 years ago as it was perturbed toward the inner solar system. Larger bodies differentiated (separated) into their ice vs rock vs metal components, upon breakup these components clustered into orbital groups.
The Tunguska event in 1908 occurred in June and is also thought to have been a comet from the Taurid meteor shower group. In fact there is compelling evidence that suggests the end of the ice age (younger Dryas event) 11,700 ka was initiated by an impact from a part of this group of Taurid meteor shower objects, a fascinating and complicated subject I will address on a later page.
The Tunguska event in 1908 occurred in June and is also thought to have been a comet from the Taurid meteor shower group. In fact there is compelling evidence that suggests the end of the ice age (younger Dryas event) 11,700 ka was initiated by an impact from a part of this group of Taurid meteor shower objects, a fascinating and complicated subject I will address on a later page.
Wiki quote
The current asteroid belt is believed to contain only a small fraction of the mass of the primordial belt. Computer simulations suggest that the original asteroid belt may have contained the mass equivalent to the Earth. Primarily because of gravitational perturbations, most of the material was ejected from the belt within about 1 million years of formation, leaving behind less than 0.1% of the original mass.
There are anywhere upwards of 2 million asteroids larger than 1,000 meters (1 km) in diameter in the main asteroid belt. The total mass of the main belt is estimated to be between 2.8 x 10^21 and 3.2 x 10^21 kg or just 4% the mass of our Moon or 22.25% the mass of Pluto. It would be reasonable to think that if 6 separate objects containing just a quarter the mass of Pluto could form molten metal pallasite rocks then so could Pluto but simulations suggest the current asteroid belt is only one tenth of one percent the mass of the original belt when these six objects were formed. In other words, the mass of the early main asteroid belt is thought to have been roughly the mass of the Earth (5.97 x 10^24) current mass of the main belt (3.2 x 10^21) x previous mass (0.1 x 10^3) = 3.2 x 10^24.
Ceres is currently the largest body (9.393 x 10^20 kg) in the asteroid belt.
Taking the assumed original mass of the asteroid belt and dividing it equally into 6 objects means each object would have been 100 times the mass of Ceres. In essence these 6 objects would have been quite large.
Before they were broken apart, they grew large enough to differentiate into layers much like Earth with its core, mantle and crust. At each layer, materials of varying densities accumulated. On breakup these layered bits were scattered into orbital disks and from time to time one of these objects is hurled at Earth and survives the trip. We compare Earth meteorites to space asteroids with particular orbital characteristics placing them into main belt family groups.
Asteroid types
The current asteroid belt is believed to contain only a small fraction of the mass of the primordial belt. Computer simulations suggest that the original asteroid belt may have contained the mass equivalent to the Earth. Primarily because of gravitational perturbations, most of the material was ejected from the belt within about 1 million years of formation, leaving behind less than 0.1% of the original mass.
There are anywhere upwards of 2 million asteroids larger than 1,000 meters (1 km) in diameter in the main asteroid belt. The total mass of the main belt is estimated to be between 2.8 x 10^21 and 3.2 x 10^21 kg or just 4% the mass of our Moon or 22.25% the mass of Pluto. It would be reasonable to think that if 6 separate objects containing just a quarter the mass of Pluto could form molten metal pallasite rocks then so could Pluto but simulations suggest the current asteroid belt is only one tenth of one percent the mass of the original belt when these six objects were formed. In other words, the mass of the early main asteroid belt is thought to have been roughly the mass of the Earth (5.97 x 10^24) current mass of the main belt (3.2 x 10^21) x previous mass (0.1 x 10^3) = 3.2 x 10^24.
Ceres is currently the largest body (9.393 x 10^20 kg) in the asteroid belt.
Taking the assumed original mass of the asteroid belt and dividing it equally into 6 objects means each object would have been 100 times the mass of Ceres. In essence these 6 objects would have been quite large.
Before they were broken apart, they grew large enough to differentiate into layers much like Earth with its core, mantle and crust. At each layer, materials of varying densities accumulated. On breakup these layered bits were scattered into orbital disks and from time to time one of these objects is hurled at Earth and survives the trip. We compare Earth meteorites to space asteroids with particular orbital characteristics placing them into main belt family groups.
Asteroid types
|
C-type 75% = (Carbon based water ice rich) occur most frequently at the outer edge of the asteroid belt, 3.5 astronomical units (AU) from the Sun, where 80% of the asteroids are of this type, whereas only 40% of asteroids at 2 AU from the Sun are C-type with Albedos in the 0.03 to 0.10 range (Extremely dark). Any asteroid containing carbon (carbonaceous) is considered organic because all organic material is built from carbon.
S-type 17% = (Silica stony, (SiO2) aka quartz or sand, water poor) with albedos typically around 0.20 (moderately bright) consists mainly of iron and magnesium-silicates. They are dominant in the inner part of the asteroid belt within 2.2 AU, common in the central belt around 3 AU, but become rare farther out. M-type 8% = (Metal mixed with stone) moderately bright (albedo 0.1–0.2). 
|
Temperature in Kelvin with relative distance from Sun
|
|
Albedo is the amount of light hitting a surface relative to the amount reflected off a surface. It’s a ratio of emitted vs absorbed/scattered light. A hundred percent of light reflected off a surface equals a bond albedo of 1.
Bond albedo is the ratio of the total flux (fluctuating inflowing light) reflected and scattered in all directions, to that incident (angle). Incident light is the available light from a source while the reflected light is the incident minus the absorbed/scattered light. For example, Saturn's moon Enceladus' bond albedo = 0.81. Out of 100 photons hitting Enceladus only 81 reflect so 81/100 = 0.81 albedo. Geometric albedo differs from bond albedo in that it is the ratio of the flux (fluctuating light) reflected head-on to that incident (available light). Enceladus' geometric albedo is 1.4. How can Enceladus reflect more than 100% light received? It doesn’t. |
Brightness of Enceladus, Earth, Moon & organic carbonaceous charcoal dark Comet 67P
|
Geometric albedo is a person’s ability to observe reflected light from a specific vantage point. If a light source (Sun) is directly behind you and an observable object is directly in front then you receive the largest possible amount of reflected light from that object assuming it isn't rotating with topographic and color variations in its terrain. But as we all know, bodies are rotating so obtaining an average brightness over time is required. On top of that if the light source is off to one side and the object is above the horizon and off to the side, this increases the amount of light scattered in directions other than toward the observer. All these factors influence the geometric albedo.
Geometric albedo is also a measure of reflected light off one body compared to a reference body. If the reference body (let’s say Saturn) reflects 10 of 100 photons back to your vantage point and the other body (Enceladus) reflects 14 out of 100 photons then the geometric albedo of that body would be 14/10 or 1.4 which is a value greater than one since it is based on a comparison to a reference body from some obtuse or acute angle but not based on the actual amount of incident light.
Geometric albedo is also a measure of reflected light off one body compared to a reference body. If the reference body (let’s say Saturn) reflects 10 of 100 photons back to your vantage point and the other body (Enceladus) reflects 14 out of 100 photons then the geometric albedo of that body would be 14/10 or 1.4 which is a value greater than one since it is based on a comparison to a reference body from some obtuse or acute angle but not based on the actual amount of incident light.
Most albedos are known in terms of geometric since we must compare one body against another body's reflected light. In the case of Enceladus, the Cassini probe gave us the ability to compare the actual light from the Sun received at Enceladus compared to light reflected off the surface hence we know both its geo and bond albedo. For other moons, planets and Kuiper Belt objects we must compare one with another and so use less accurate geometric albedos and so some degree of error exists.
|
Stars emit light. The redder the emitted light the cooler the star. The Hertzsprung-Russell diagram was created to show how stars cluster into groups by size color temperature and brightness. Light reflecting off objects in our solar system display characteristic traits as well. |
|
|
In this table >>>>>>>>>>
Plutinos = objects in 3:2 resonance with Neptune. Comets = ice dominant bodies beyond 3 AU Centaurs = exist between 5 AU and 30 AU SDO's = Neptune Scattered Disk Objects Cubewanos = Kuiper Belt Objects 30-50 AU Trojans = objects in 60° lead/lag L4,L5 Lagrange zone |
B-V = Blue minus Visible, V-R = Visible minus Red, V-I - Visible minus Infrared
|
|
To easily remember the difference between a Trojan object and a Centaur. Trojan's (like a horse) run 60° ahead of and behind planets |
Centaurs are a mix of asteroids (mythical half man, half horse) and comets scattered randomly among the outer gas giants. |
By Adam Jones from Kelowna, BC, Canada - Replica of Trojan Horse - Canakkale Waterfront - Dardanelles - Turkey, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=64144380
|
|
|
What are some reasonable assumptions we can make based on this color table? Can we say Plutinos and Kuiper Belt Objects are (generally speaking) redder than Jupiter Trojans? |
|
|
Pluto is reddish brown while Charon is more blueish gray suggesting they are most likely from different zones in the solar system mixed together by Neptune in the same way Scattered Disk Objects are multicolored and scattered by Neptune. Neptune's orbital path is thought to have migrated outward, as it did, it scrambled up the objects that got too close. This then created the scattered disk objects SDO, the mixed colors of objects around the gas planets. Neptune's migration also put a lot of objects into resonant pulses with it and probably caused Haumea to collide with something creating the blueish Haumea family of objects. The bright albedo of the Haumea collisional family indicates this collision occurred within the last billion years. Neptune's migration outward is also credited with creating the late heavy bombardment. Neptune's migration outward wreaked havoc in our solar system. |
|
http://adsbit.harvard.edu//full/1996AJ....112.2310L/0002311.000.html
|
Title: Color Diversity Among the Centaurs and Kuiper Belt Objects
Authors: Luu, J. & Jewitt, D.
|
Above is a table with accompanying chart showing how KBO are reddish and Centaurs (gravitationally perturbed objects by Jupiter) are mixed between blueish and reddish.
Above, I put together some tables showing color comparisons of various objects with size and albedo.
Knowing the reflected brightness of an object in the solar system helps us understand its size which is necessary if you want to understand its density which is necessary if you want to understand its composition.
Light carries information.
Knowing the reflected brightness of an object in the solar system helps us understand its size which is necessary if you want to understand its density which is necessary if you want to understand its composition.
Light carries information.
|
UV IR
|
|
|
<<<<<<< Hubble Space Telescope’s (HST) The Wide Field Camera 3 (WFC3) houses 63 UV filters in the Ultraviolet Imaging Spectrograph Subsystem (UVIS) of HST and 17 in the Infrared (IR) channel >>>>>>>>>> |
|
|
F606 & F814W are light filters which cover the majority of the visible and near visible range of the electromagnetic spectrum of light and are used to produce spectral charts like this.
<<<<<<< This help's us understand the composition of components in/on solar system bodies. |
|
|
There are long pass, wide, medium & narrow spectra filters identifying electromagnetic waves from 2,000-10,000 angstroms (aka 200-1,000 nm, or 0.2-1.0 microns).
Dips aka lines of absorption in the spectrograph occur as gasses absorb energy from light at specific points along the light spectrum. These dips or darkened zones (lines of absorption) leave a finger print which identify elements and compounds. In this image the dark absorption bands appear as lines of emission which occur as the result of emitted not reflected light. |
|
Early on scientists noticed a peculiar gap in the distance between Mars and Jupiter (1.52 AU to 5.2 AU) and expected to find a planet in this region but instead began to find small fragments or as we call them today, asteroids. Ceres is the largest of the asteroids and is rounded by its gravity and has been reclassified more than once. Currently Ceres is called a dwarf planet. Ceres does have a carbon based spectroscopic signature and is now thought to have formed further out and was perturbed inward. Kirkwood gaps help isolate some of the main belt asteroids into family groups.
Beyond the asteroid belt is where the gas giants dominate (5 AU to 30 AU) with their many varied moons some of which were once asteroids or comets. The vast majority of the moons are ice balls with various concentrations of dust and gravel but water ice dominates in this zone. Lighter super volatile gasses like carbon monoxide and nitrogen are detected less on the surface of smaller bodies (moons) in this zone but larger bodies like Titan can gravitationally hold onto these lighter volatile gasses.
If the entire solar system was originally constructed of the same stuff and water ice dominates in the zone beyond 4 AU where its too cold for the Sun to evaporate water ices then prior to the Sun's ignition, all bodies in the solar system that were forming from the solar nebula were water rich including the four inner terrestrial planets (Mercury, Venus, Earth/Moon & Mars). As a matter of fact its now known (page 75) that the Earth was a water world long before the late heavy bombardment (LHB).
Scientists analyzed 4.4 billion year old zircon mineral grains from the Jack Hills of Western Australia and concluded early Earth was a water world half a billion years prior to the LHB. Additionally, the water on Earth does not match deuterium ratios found in comet 67P and so was not primarily delivered by comets or asteroids. I'm saying, Earth was basically a comet (water ice rich body) prior to the Sun's ignition and it had a magnetosphere just like Jupiter's moon Ganymede which helped preserve its low deuterium ratio water once the Sun ignited.
Further out in the zone beyond Neptune (30 AU) (Transneptunian zone) conditions are so cold with so little energy that even super volatile ices exist as solids on the surface of bodies depending on the size (gravitational pull) of that body. This is a one to one ratio, as the temperature drops the size of the body required to hold onto volatile gasses drops.
If the entire solar system was originally constructed of the same stuff and water ice dominates in the zone beyond 4 AU where its too cold for the Sun to evaporate water ices then prior to the Sun's ignition, all bodies in the solar system that were forming from the solar nebula were water rich including the four inner terrestrial planets (Mercury, Venus, Earth/Moon & Mars). As a matter of fact its now known (page 75) that the Earth was a water world long before the late heavy bombardment (LHB).
Scientists analyzed 4.4 billion year old zircon mineral grains from the Jack Hills of Western Australia and concluded early Earth was a water world half a billion years prior to the LHB. Additionally, the water on Earth does not match deuterium ratios found in comet 67P and so was not primarily delivered by comets or asteroids. I'm saying, Earth was basically a comet (water ice rich body) prior to the Sun's ignition and it had a magnetosphere just like Jupiter's moon Ganymede which helped preserve its low deuterium ratio water once the Sun ignited.
Further out in the zone beyond Neptune (30 AU) (Transneptunian zone) conditions are so cold with so little energy that even super volatile ices exist as solids on the surface of bodies depending on the size (gravitational pull) of that body. This is a one to one ratio, as the temperature drops the size of the body required to hold onto volatile gasses drops.
Comets
Comet 67P is a short period comet. It obits the Sun in about 6 years. It came from the KB and is ice rich, hence, it vents jets of sublimated ice vapor when it gets close enough to the Sun and forms a coma. If Comet 67P remained in the Kuiper Belt it would be called an asteroid. This seems illogical to me. When 67P is not venting gasses within its current orbit it is still called a comet. It doesn't become a comet when near the Sun then become an asteroid when not venting gasses. Its composition is the same as when it was in the KB.
This seems a peculiar thing to me. Why are bodies in the KB called asteroids while those same bodies closer to the Sun are called comets. To me an asteroid is rock rich while a comet is water ice rich. An asteroid is basically a comet that has had its ices largely evaporated away by the Sun dictated primarily by where it resides relative to the frost line in the Main Asteroid Belt. Kuiper Belt objects have not had their volatile ices evaporated and consequently should be considered an ice rich comet without a coma not a rock rich non volatile asteroid.
This seems a peculiar thing to me. Why are bodies in the KB called asteroids while those same bodies closer to the Sun are called comets. To me an asteroid is rock rich while a comet is water ice rich. An asteroid is basically a comet that has had its ices largely evaporated away by the Sun dictated primarily by where it resides relative to the frost line in the Main Asteroid Belt. Kuiper Belt objects have not had their volatile ices evaporated and consequently should be considered an ice rich comet without a coma not a rock rich non volatile asteroid.
|
Comet 67P is thought to have come from the Kuiper Belt (50 AU).
Comet 67P has a hard outer shell with at least 8 inches of dust with a very porous core similar in ways to an egg. The unusually high porosity of the interior of the nucleus provides the first indication cometary growth could not have been from violent collisions, as these would have compacted the fragile internal material. Comet 67P is also a bylobed object constructed of two roughly same sized and compositionally similar objects which grew individually then conjoined gently enough not to rupture their outer crusts' (egg shell). Thirty percent of transneptunian binary pairs (TNB) are similar in size and composition page 66. |
|
|
It appears, similar sized comets/asteroids with similar compositions that are mutually captured into a binary pair is relatively common in the Kuiper Belt. I suspect the reason has to do with the similarity in size/mass.
If one object is much larger than the other, the larger object will either eject or gravitationally attract the smaller object. similarly sized objects have similar mass with a similar centrifugal gravity breaking effect as they drift closer and closer. As two bodies get closer in an orbital dance, their collective spin speed increases to preserve their angular momentum. As they get closer to colliding and their spin velocity increases their centrifugal force (outward flinging) grows which in turn slows their impact speed. Basically their closely related gravitational pull (escape velocity) causes a somewhat balanced centrifugal orbital velocity that cancels against each other nullifying the (collision velocity) affect of their individual gravitational pull. |
|
This, I suspect, is how an object like comet 67P constructed of two cotton candy like interiors and a brittle outer shell could survive the merge between these similarly sized objects.
Meteorites on average are 94% stone, of that stone 86% is chondritic (round pebbles and space dust), 8% of the stone is achondritic (cooled lava from a differentiated core body).
This chart shows the relative amount of potasium (K) and uranium (U) on various solar system bodies. Chondrites contain less Uranium (1/100 gram per ton of rock) than Potasium (10^2.7 grams about one pound/ton of rock) than any other type of listed body while basaltic achondrites contain more U than K. In other words 86% of meteorite material contains larger quantities of K than U as a radiogenic heat source. From this paper The K/U ratio of the silicate Earth: Insights into mantle composition, structure and thermal evolution I pulled the below chart showing the relative contribution of U, K and Th radiogenic heating of our Earth's core.
|
|
|
Potassium's contribution to Earth's heat has been decreasing steadily. Today it is contributing less than 20% of the heat provided by radioactivity. Eighty six percent of the material in meteorites (chondrites) which contain a higher ratio of potassium relative to uranium is only contributing 20% of the heat from radiation. If these values can be extrapolated to Pluto and if Pluto has a differentiated core then potassium would be the most abundant radioactive material in its core providing the least amount of heat energy to that core. The dominant available quantity of radiogenic material (K) inside Pluto is currently providing the least amount of heat. |
|
A radioactive hot core of U and K are used by mainstream scientists to explain
I'm still in favor of tidal flex and tidal stress energy as an explanation for Pluto's geological activity.
Earth's Moon has moonquakes. Moonquakes have been found to occur deep within the mantle of the Moon about 1,000 km below the surface. These occur with monthly periodicities and are related to tidal stresses caused by the eccentric orbit of the Moon about the Earth. While Pluto and Charon do not have eccentric orbits with each other they are both in orbital resonance with Neptune. Pluto's axis wobbles (precesses) 20°, as it does, it has to drag Charon and the small moons along in a lead lag scenario. Both of these conditions (axial wobble & Neptune resonance) could induce internal flexing in turn producing a small amount of tidal flex energy perhaps just enough to squeeze out some of the most super volatile gasses like N2, CH4, CO.
Excerpt from early interview with Bill McKinnon regarding Pluto
The researchers emphasized they don’t have any direct evidence for an interior liquid ocean, but will investigate the possibility as data continue to trickle in over the next 16 months... ” McKinnon said.
In the 16 months that followed, no new data arrived that supported the existence of an interior liquid ocean. The only thing that changed was the frequency with which members of the New Horizons team kept speculatively repeating the concept that there might be an ocean.
If you repeat something enough and the media jumps on it, by virtue of repetitive regurgitation it becomes accepted as fact. Today everyone accepts there is a subsurface ocean on Pluto simply because its been repeated frequently but we have the same amount of supportive data today as we had when Bill McKinnon made the above statement and that statement emphasizes there is NO DIRECT EVIDENCE supporting the existence of an interior liquid ocean. Nobody seems to be saying this today! Instead Alan Stern takes this water ocean assumption to the next and ridiculous level of suggesting there might be intelligent life below Pluto's icy crust (page 84).
Francis Nimmo paper prior to the flyby
In most of our models present-day Pluto consists of a convective ice shell without an ocean. However if the reference viscosity is higher than 5×10^15 Pas, (More than two times the pressure inside a W80 nuclear warhead detonation (64 billion bar) https://en.wikipedia.org/wiki/Orders_of_magnitude_(pressure) the pressure at the core of the Earth is 360×10^11 Pas and Pluto is 0.00218 times the mass of Earth or stated another way, Pluto is two tenths of one percent of Earth's mass) the shell will be conductive and an ocean should be present.
If Pluto never developed an ocean, predominantly extensional surface tectonics should result, and a fossil rotational bulge will be present... A present-day ocean implies that compressional surface stresses should dominate, perhaps with minor recent extension (instead we see the exact opposite conditions, extensional faults dominate while compression stresses are minor inferring there is no ocean). An ocean that formed and then re-froze should result in a roughly equal balance between (older) compressional and (younger) extensional features.
These predictions may be tested by the New Horizons mission. (The only thing New Horizons determined was that there are more expansion fractures than there are compression ridges. No data collected by New Horizons remotely suggests there is an ocean. The concept of a subsurface ocean is complete conjecture. Nimmo makes an interesting point, extensional features are a sign of youthful activities. Both Pluto and Charon display extensional (younger) features.)
Highlights
► We modeled Pluto’s coupled thermal and spin evolution.
► Whether Pluto develops an ocean depends on the balance between heat transfer and radiogenic heating.
► In most of our models present-day Pluto consists of a convective ice shell without an ocean.
- Pluto's geological activity
- Hypothetical convective currents in the polygonal cells at Sputnik Planitia creating the elevated central mound,
- This convection process somehow takes place on top of a 64 km insulating layer of conductive ice
- A hypothetical subsurface ocean
- A hypothetical positive gravity anomaly
- Observational evidence suggests a negative gravity anomaly.
- True polar wander (skin slip)
- Observational evidence indicates Pluto's skin slip direction (SE to NW) suggests SP is a negative gravity anomaly
I'm still in favor of tidal flex and tidal stress energy as an explanation for Pluto's geological activity.
Earth's Moon has moonquakes. Moonquakes have been found to occur deep within the mantle of the Moon about 1,000 km below the surface. These occur with monthly periodicities and are related to tidal stresses caused by the eccentric orbit of the Moon about the Earth. While Pluto and Charon do not have eccentric orbits with each other they are both in orbital resonance with Neptune. Pluto's axis wobbles (precesses) 20°, as it does, it has to drag Charon and the small moons along in a lead lag scenario. Both of these conditions (axial wobble & Neptune resonance) could induce internal flexing in turn producing a small amount of tidal flex energy perhaps just enough to squeeze out some of the most super volatile gasses like N2, CH4, CO.
Excerpt from early interview with Bill McKinnon regarding Pluto
The researchers emphasized they don’t have any direct evidence for an interior liquid ocean, but will investigate the possibility as data continue to trickle in over the next 16 months... ” McKinnon said.
In the 16 months that followed, no new data arrived that supported the existence of an interior liquid ocean. The only thing that changed was the frequency with which members of the New Horizons team kept speculatively repeating the concept that there might be an ocean.
If you repeat something enough and the media jumps on it, by virtue of repetitive regurgitation it becomes accepted as fact. Today everyone accepts there is a subsurface ocean on Pluto simply because its been repeated frequently but we have the same amount of supportive data today as we had when Bill McKinnon made the above statement and that statement emphasizes there is NO DIRECT EVIDENCE supporting the existence of an interior liquid ocean. Nobody seems to be saying this today! Instead Alan Stern takes this water ocean assumption to the next and ridiculous level of suggesting there might be intelligent life below Pluto's icy crust (page 84).
Francis Nimmo paper prior to the flyby
In most of our models present-day Pluto consists of a convective ice shell without an ocean. However if the reference viscosity is higher than 5×10^15 Pas, (More than two times the pressure inside a W80 nuclear warhead detonation (64 billion bar) https://en.wikipedia.org/wiki/Orders_of_magnitude_(pressure) the pressure at the core of the Earth is 360×10^11 Pas and Pluto is 0.00218 times the mass of Earth or stated another way, Pluto is two tenths of one percent of Earth's mass) the shell will be conductive and an ocean should be present.
If Pluto never developed an ocean, predominantly extensional surface tectonics should result, and a fossil rotational bulge will be present... A present-day ocean implies that compressional surface stresses should dominate, perhaps with minor recent extension (instead we see the exact opposite conditions, extensional faults dominate while compression stresses are minor inferring there is no ocean). An ocean that formed and then re-froze should result in a roughly equal balance between (older) compressional and (younger) extensional features.
These predictions may be tested by the New Horizons mission. (The only thing New Horizons determined was that there are more expansion fractures than there are compression ridges. No data collected by New Horizons remotely suggests there is an ocean. The concept of a subsurface ocean is complete conjecture. Nimmo makes an interesting point, extensional features are a sign of youthful activities. Both Pluto and Charon display extensional (younger) features.)
Highlights
► We modeled Pluto’s coupled thermal and spin evolution.
► Whether Pluto develops an ocean depends on the balance between heat transfer and radiogenic heating.
► In most of our models present-day Pluto consists of a convective ice shell without an ocean.
|
This is what F. Nimmo was saying prior to the flyby, however, today with no additionally supportive data he supports the hypothesis that there is a subsurface ocean created by a radioactively hot core.
The only thing added since these statements by Nimmo and McKinnon are models bent and twisted to create single minded outcomes while ignoring some basic fundamental observational facts. Objects in a Neptune orbital resonance with radius larger than 600-700 km tend to be brighter (higher albedo) than non resonant objects suggesting resonance is the engine driving their resurfacing not radioactivity.
|
|
|
There are exceptions to every rule but the trend exists.
Objects with bright albedos suggest their surfaces are renewed and there is a correlation with the renewed surfaces and their orbital interaction with Neptune. Pluto is in a 3:2 resonance with Neptune. The monkey speaks his mind. |
|