Abstract:
Earth is the water planet. Liquid water covers more than 70% of the surface and dominates all surface processes, geological, meteorological, and biological. However the hydrosphere composes only about 0.025% of the planet’s mass, so that small amounts of H incorporated into the oxygen minerals of the interior may constitute the majority of Earth’s total water. The Earth is thought to be generally similar in composition to the chondrite meteorites which average about 0.10% by weight H2O. So if the Earth were strictly chondritic in its H content, about 75% of that H as water would have either been tied up in the minerals of the interior or lost to space. Understanding how H behaves at the atomic scale in these materials will help us to understand how the Earth balances and retains its water and may help us to understand how water planets develop and how common they might be.