Jupiter’s Early Luminosity May Have Driven off Io’s Initial Water Inventory

Abstract

After its formation, Jupiter was substantially more luminous than it is at the present day (104 times). Right after formation, the inner satellites Io and Europa would have received an order-of-magnitude larger incoming flux from Jupiter, than solar insolation. However, little work has been done to examine the impact this would have had on the Galilean satellites. In this work we explore the possibility that Jupiter’s early luminosity could have caused the loss of any initial water inventory on Io and Europa. We find that, depending on Jupiter’s luminosity after the proto-Jovian disk dissipates, heating from Jupiter could drive rapid water loss via hydrodynamic escape. If early tidal heating dehydrated Io’s accreted silicates, this may provide a mechanism to lose Io’s initial water inventory.