Volcanic Activity on Exoplanets

In 1979 it was predicted that the Voyager spacecrafts would detect volcanic activity on the surface of Io, which was later confirmed. The volcanic activity on Io is driven by tidal heating from Jupiter. There is a runaway melting mechanism, outlined on the right, that was used to predict the volcanism on Io.

In Seligman et al. 2024, we generalized this tidal heating model to larger exoplanet orbiting low mass stars. We show that this runaway melting mechanism is generic for a composite planetary body with liquid core and solid mantle as long as tides deposit sufficient energy, and the planet has nonzero eccentricity.

We then show which currently known exoplanets would be good candidates for exhibiting Io like volcanic activity that could be detected with JWST. From all currently confirmed exoplanets, we find that the terrestrial planets in the L98-59 system are the most promising candidates for sustaining active volcanism. We generated synthetic transmission spectra of these planets assuming Venus-like atmospheric composition and found that the volcanic activity may be observable with 5-10 transits with JWST for L98-59bcd.