Water and land surfaces on a planet interact in particular ways with gases in the atmosphere and with
radiation from the star. These interactions define the environments that prevail on the planet, some of which may be more amenable to prebiotic chemistry, some to the evolution of more complex life.
Meanwhile, the bulk compositions of exoplanets are inferred from measuring their bulk density (mass and radius). But on relatively volatile-poor planets, like Earth, atmospheres and oceans would not make a dent in observed bulk density. To infer anything about the volatile contents and more detailed silicate composition of a presumably-rocky exoplanet, we therefore take advantage of the wealth of knowledge from the geosciences.
In this seminar, Claire will introduce how thermodynamic modelling is used, constrained through a long history of experiments, to understand the compositional diversity of presumably-rocky exoplanets. She will go on to speculate on whether Earth’s land/ocean ratio is a rare or common outcome of planetary evolution.