February 10th, 2017

Pluto/Charon
Their Story - Not Ours

As my knowledge about Pluto/Charon has grown, the story I see them expressing has evolved. The basics have remained constant but the details have adjusted to align with more accurate detailed  information and scientific findings.

Here's how I see the Pluto/Charon story based on the science and observational evidence.

The Nice model or planet migration concept suggests Neptune formed early in our solar system's history, it was located about 5.5 to 17 AU from the Sun and was closer than Uranus.

Saturn and Jupiter formed out of the early solar nebula in the first 3-4 million years and set up a resonant pulse which aligned with Neptune at some point and kicked it into a higher orbit.

This caused Neptune to cross paths with Uranus and disrupted a heavily populated planetesimal debris field from 15 to 37 AU hurling them around creating the late heavy bombardment. The solar system is considered to be about 4.5 byr old.

This Hal Levison model suggests, Neptune took about 900 million years to get kicked outward and migrate to its current orbital distance.

Neptune arrived at its current orbit around 3.6 byr ago. As more time passed, Neptune was able to set up low pressure zones 60 degree's ahead and behind called Lagrange points.

There were also resonant frequency zones where every time an object orbited the Sun twice Neptune orbited three times these are called 2:3 resonant objects or Plutinos.

This process also pushed Pluto into an eccentric orbit ranging from 30 to 50 AU from the Sun at an inclination of 17 degrees to the ecliptic plane.

This is probably how Pluto was built into the largest of the Kuiper belt objects as it is shepherded with other objects in Neptune's 2:3 resonant zone.

Migrating near then far from the Sun, Pluto with it's compositional make up of nitrogen (N2), methane (CH4), carbon monoxide (CO) along with solar radiation was able to produce tholins. Carl Sagan produced these long chain complex hydrocarbons in a lab which he named tholins.

Charon on the other hand developed and remained for most of its formative years at a zone distinctly different than Pluto's, hence it is compositionally unlike Pluto.

Objects 30 AU from the Sun developed differently than those at 50 AU. One difference was that distances between objects in the 50 AU zone were further apart and less numerous thus growing slower due to fewer impacts. Charon was introduced to Pluto after Pluto grew to a relatively larger size.

Pluto was in the 2:3 resonance zone of Neptune causing more collisions which built it into it's current size.

According to Hal Levison this process didn't even begin until about 3.6 billion years ago.

A Paper titled "The inner solar system cratering record and the evolution of impactor populations" says this.
The LHB (Late Heavy Bombardment) began some time before 3.9 Ga, peaked and declined rapidly over the next 100 to 300 megayears, and possibly more slowly from about 3.8–3.7 Ga to 2 Ga.

Wiki quote about the time of the LHB.
As more data has become available, particularly from lunar meteorites, this theory (LHB), while still controversial, has gained in popularity... Consistent with the cataclysm hypothesis, none of their ages was found to be older than about 3.9 Ga. Nevertheless, the ages do not "cluster" at this date, but span between 2.5 and 3.9 Ga.

After another 2.6 to 3 billion years of collisional growth, Pluto and Charon formed into compositionally different objects with uniform cores.

They are too cold and small to self differentiate with densities of 1.854 and 1.702 g/cm3 without some form of tidal flex energy.

Both planets were spinning around their own axis and their poles were oriented differently. As they danced around each other, their gravitational perturbations on each other caused them to torque twist and turn over into their current 120 degree tilt. Pluto's axial tilt ranges from 102 to 126 degrees. I've suggested this wobble is created by gyroscopic gravitational Torque Induced Tilt due to uneven mass distribution.

Around .7 to 1 billion years ago Neptune finally nudged Pluto and Charon within each others gravitational field of influence which initiated an eccentric orbital dance between the pair.

Pluto having  eight times the mass, twice the size and gravity of Charon (.620 m/s2 vs .288 m/s2) pulled Charon into its orbit.

It would be absurd to think objects hit both Pluto and Charon spinning them both over at the same 120 degree angled axial tilt.

Impacts do not create axial tilt, gyroscopic gravitational torque does as it seeks to balance the uneven distribution of their collective mass.

This twisting torque caused their interiors to heat slightly from all the tidal flexing energy required to despin and tilt them onto their sides.

The eccentric orbits along with their individual axial spin and torque induced tilt created tidal flex and internal heat pressure separating out the silicate rock creating a small internal warm ember of a core.

Animation by James Keane intended to present a different idea than mine. I'm using it to demonstrate torque induced tilt.

Pluto's crust may slip and slide atop subsurface fluids of N2 creating linear striations. This crustal slip is called true polar wander as the spin axis keeps its original orientation and the crust slides to a different position.

Charon being mostly hard water ice with a smaller diameter was able to keep it's internal pressure contained under its more brittle relative thick crust similar to a shaken soda can just waiting to blow.

Pluto, on the other hand, with it's softer gas mixtures of N2, CH4, CO along with its larger size and relative thinner crust frequently cracked under the expansion pressure and tidal bulge effect.

This allowed Pluto to gradually blow off steam while Charon became more like a pressure cooker.

Less than 20 million years ago Pluto became tidally locked to Charon then an object similar to the red comet 1994 Jr1 impacted Charon on its north pole at Mordor.

Ammonia hydrates identified on the moons Styx, Nix Hydra indicate these fragments called moons ejected off Charon and Pluto are younger than 20 million years.

Green blotches are ammonia

Charon at half the size of Pluto stopped it's axial spin first while Pluto spun down slowly.

As Pluto's axial spin slowed, the tidal bulge crept around the planet fracturing the crust releasing pressure by spilling out fluid onto the surface and venting gasses creating an atmosphere. Pluto's summer years (62yrs/season) would aid in this process.

The fractures froze and sealed forming scar tissue on Pluto's crustal skin called expansion fractures as can be seen at the spider.  

Since ammonia hydrates are so easily torn apart by the Sun's photons the moons or at least the surface ammonia must be young or the ammonia must be renewed from subsurface processes. Charon and the small moons are geologically dead so the ammonia is not refreshed from internal forces but it is present. 

In this process called photolysis or photodissociation
photons from the Sun will completely disassemble ammonia hydrates within 20 million years at Pluto's distance from the Sun.

One scientific paper also states the surface of Charon heated to >90K within the last 100,000 years, evidenced by its crystalline structure which would amorphize within 100 k years.

At this point in their story, Charon had a great deal of pent up pressure from its eccentric tidal flex dance with Pluto and was then impacted on the north pole.

The shape of photons

Charon let loose one big diagonal break popping off fragments from the southern hemisphere like a shaken can of soda suddenly slammed  to the ground exploding under the stress created by the impact at Mordor.

Some fragments went into high orbit creating Hydra and Kerberos others fell back onto Charon's surface while a focused group of shards were directed at Pluto by its gravity hitting it primarily on the southern hemisphere facing Charon.

This created large angular disruptive patterns on Pluto's side facing Charon.

The high erratic spin of the small moons, their poles not aligning with Pluto/Charon's, the ammonia hydrates, the reflectance (albedo) and the tholin impact crater on Nix all say these moons are younger than 20 million years. Charon's surface indicates this happened within the last 100,000 years.

The north pole impact at Mordor on Charon ejected shards that impacted Pluto these impacts sent multiple compression waves (P waves) through Pluto which was also under pressure from all the recent tidal flexing.  

These multiple compression waves traveled through Pluto to the opposite side south of Sputnik Planitia and knocked chunks off Pluto creating the deep pits as well as the low orbiting moon Nix.

Other bits ejected from Pluto were covered in tholin one of which eventually hit Nix creating its red impact crater. 

The chunks knocked off Pluto allowed subsurface fluids to back fill the void creating a sink hole of sorts below the crust at SP which is directly opposite Charon's gravitational pull. 

Pluto's crust then collapsed inward at SP. This collapse squeezed more of the dense N2 fluids out from below creating a long N/S oriented crack along SP's western edge.

The fluid and gasses continue to boil up from below SP primarily along its western edge and the gasses continue to create an atmosphere. Atmospheres don't create oceans rather oceans create atmospheres thus the welling up fluid and gasses at SP have created the methane snow fog and atmosphere at Pluto.

Because of Pluto's 120 degree tilt it experiences 62 year seasons as it travels around the Sun. This further helps cyclically heat and cool areas on Pluto altering the heat at SP in turn changing the atmospheric conditions.

This is Pluto and Charon's story with as much scientific accuracy and observational evidence I can muster.

I can't express how much I appreciate all the help I've received from smart people and scientist on this journey of discovery.

Thank you Alan Stern and the New Horizons team that made this all possible.

< Page 61 Ammonia

Flow Page 63 >