Tholins - any data on the bulk properties of "star tar"?, It's red, it's a polymer, what else do we know? Options

[HSchirmer]

Topic moved to Chit-Chat from Pluto/KBO since it is not mission-specific- Admin



Is there any recent research into predicting the bulk properties of tholins on KBOs?
IIRC, Carl Sagan coined "tholin" as a better term for naturally-occurring-outer-solar-system-polymers, aka "star tar".
Tholins are naturally occurring polymers; in plain language, KBOs acquire a surface coating of "space plastic".

I'm curious for three reasons -

First, at Ultima Thule, we are seeing the first body where the bulk properties of surface tholins might have a significant or even dominant effect on surface morphology.
Gedanken experiment:
let's take Car Sagan's words at face value - tholins are "star tar" that builds up over time on outer solar system surfaces.
Well, when you add earth tar to earth dust, sand, gravel, and rock, you get asphalt pavement, which makes up the roads and parking lots and bike paths we are familiar with. It's sticky, coherent, and exhibits plastic deformation.
What if Ultima-Thule has a coating of "star asphault" (tar + regolith) on its surface?
Depending on the exact properties of the tholins (elasticity, plasticity, stress, strain, shear modulus)
a star-tar tholin skin could mean that Ultima and Thule are effectively giant bean bag chairs-
The outer "skin" of tholin-bound-regolith ascts like asphalt- it is a coherent surface, it deforms plastically under medium stress, but breaks under high stress.
The interior might be composed of loosely bound "goosebumps" or "dragon eggs" that are 10' / 3m diameter "accretion pebbles";
these would be functionally equivalent to the to the polystyrene beads in a bean bag chair.
In that case, Ultima Thule is, literally, a giant beanbag chair, with divots and ridges reflecting the effects of slow speed impacts.

Second, the bulk properties of a polymer (e.g. "plastic") and thus a tholin, could vary wildly depending on the specific composition and ratio of the polymer subunits you start with.
Make a polymer with vinylidene chloride and you get saran wrap (weak and stretchy), make the same polymer with vinyl chloride and you get PVC pipe (strong and tough), make it with carbonate, you get bulletproof glass (effectively impenetrable).
Getting some idea of the range of Tholin/polymer properties would really help to understand the bulk properties of "Tholin" on the surface of a KBO- does the Tholin coating act like tar and bind the surface regolith together in a sticky-flowing way, does it act like saran wrap and bind the surface regolith into a flexible sheet, or does it act like polycarbonate and bind the regolith into a hardened shell. Each is amazing in its own way.

Third, and most whimsically, there's a recent paper which notes that the dark-red tholin colored interstellar asteroid ‘Oumuamua accellerated away from the sun as if it were a thin sheet.
Perhaps it was: ever seen mud cracks or mud curls?
Imagine a sheet of tholin-reinforced-surface-regolith blasted off a distant exo-KBO by an impact, now fluttering through space.


Post Script- sometimes nature achieves "breakthroughts" without intelligence or civilizations-
Oklo- the first nuclear reactor on Earth turned on 2 Billion years ago without human involvement
‘Oumuamua acted like a lightsail but perhaps it's just a sheet of exo-tholin?