Scientists have modeled the appearance of cryovolcanoes on Pluto’s moon Charon 22:32

Scientists have modeled the depths of Charon to explain the appearance of canyons and cryovolcanoes on it. article about it published in Icarus.

The model is based on data obtained by the New Horizons spacecraft during its transit of Pluto in 2015. Scientists were surprised that Charon had traces of cryovolcanic activity, even though this body was believed to be geologically “dead.” According to the hypothesis that the study’s authors decided to test, in ancient times Charon had an ocean that had frozen over time. This was included in the model – the liquid consisted of a mixture of water and ammonia in various configurations. Ammonia can act as an antifreeze and extend the life of the liquid ocean.

As the ocean freezes and a new layer of ice forms inside the ice crust, the pressure inside the ocean rises. Therefore, water enters the cracks and splashes to the surface under pressure, forming a cryovolcano – an analogue of an earthly volcano – and forming a canyon. However, based on current models of Charon’s internal evolution, the ice crusts were too thick to completely break apart under the stresses associated with freezing oceans. The timing of the ocean freezing is also important. The synchronized and circular orbits of Pluto and Charon stabilized relatively early, so tidal warming occurred only in the first million years of their existence.

“Either Charon’s ice crust was less than 10 km thick at the time of the flow burst, as opposed to the 100 km accepted in science, or the surface was not in direct contact with the ocean at the time of the eruption,” the scientists explain.

In other words, if we accept the hypothesis tested by the authors about the connection of canyons and volcanism to the ocean, then either the thickness of the ice crust during the eruption of the ice was much thinner than previously thought, or there was an unknown heat source in the bowels of Charon. Most likely, according to the authors, the hypothesis about the connection of the canyons with the ocean is wrong, and they were formed during eruptions of liquids from smaller gaps.