Relevance of tidal heating on large TNOs

We examine the relevance of tidal heating for large Trans-Neptunian Objects, with a focus on its poten-
tial to melt and maintain layers of subsurface liquid water. Depending on their past orbital evolution,
tidal heating may be an important part of the heat budget for a number of discovered and hypothetical
TNO systems and may enable formation of, and increased access to, subsurface liquid water. Tidal heat-
ing induced by the process of despinning is found to be particularly able to compete with heating due
to radionuclide decay in a number of different scenarios. In cases where radiogenic heating alone may
establish subsurface conditions for liquid water, we focus on the extent by which tidal activity lifts the
depth of such conditions closer to the surface. While it is common for strong tidal heating and long lived
tides to be mutually exclusive, we find this is not always the case, and highlight when these two traits
occur together. We find cases where TNO systems experience tidal heating that is a significant propor-
tion of, or greater than radiogenic heating for periods ranging from100

s of millions to a billion years. For
subsurface oceans that contain a small antifreeze component, tidal heating due to very high initial spin
states may enable liquid water to be preserved right up to the present day. Of particular interest is the
Eris-Dysnomia system, which in those cases may exhibit extant cryovolcanism.