event
Wednesday 23 Feb 2022: Sublimation-driven convection in Sputnik Planitia on Pluto
Adrien Morrison -
4th Floor physics + remote 14:00-15:00
The flyby of Pluto in 2015 by New Horizons gave us a wealth of observations
showing the dwarf planet is still surprisingly active. A particularly striking feature
is Sputnik Planitia, an impact crater filled with nitrogen ice. Its surface exhibits
polygonal patterns that have been immediately identified as a marker of solid-state
convection occurring in the ice. However, the buoyancy source remained unclear as
existing models predicted patterns that are inconsistent with the ones observed. We
show in this study that sublimation of the ice could, by pumping latent heat out of
the underlying ice, power convection in Sputnik Planitia in a way that is consistent
with observations. This would make Sputnik Planitia the first known solid layer with
planetary scale dynamics that are powered by climate instead of internal sources.
