Geophysical Research Letters

The coupled orbital and thermal evolution of Triton



The coupled orbital and thermal evolution of Triton is simulated with a model of the satellite having temperature dependent k/Q (k is the second degree Love number and Q is the tidal dissipation factor). Large changes in orbital and interior properties occur in a short time span of less than 108 years. The peak tidal heating rate exceeds the radioactive heating rate by a factor of at least 103. The ability of tidal heating to overwhelm solid state convection and cause global melting is unequivocally demonstrated. Triton's initial thermal state and composition are shown to control the length of time that passes between capture from heliocentric orbit and the occurrence of swift and dramatic changes in orbital and internal properties. This time interval could have been several billion years.