True Polar Wander of Lava Worlds

Abstract

As one of the most detectable types of terrestrial planets, lava worlds are highly prioritized targets for exoplanet atmosphere characterization since their atmospheres may reveal what they are made of and how. Our work examines the possibility of true polar wander (TPW) occurring on these ultrahot tidally locked planets, powered by mass redistribution from atmospheric flow between the hot permanent dayside and the cold permanent nightside. We find that lava planets within a certain mass and temperature range may undergo TPW, and this likelihood increases with star mass. As a result of TPW, the magma ocean and atmospheric compositions may be less evolved (refractory-enriched) than previously thought and may be validated by exoplanet demographic surveys.

Keywords

• Exoplanet evolution
• Exoplanet atmospheric evolution
• Exoplanet atmospheres