For decades, planetary scientists have been arguing about how the Earth acquired its oceans.  Maybe the water came from volcanic outgassing, or was delivered by icy comets, or came from a bombardment of asteroids over geologic time.  Models of the Earth’s formation show that our planet didn’t form with enough water to account for its present oceans – that means the water came from somewhere else.    But maybe our … Continue reading Ask not where Earth got its water…