Evolution of Hydrogen in the Inner Solar System
The goal of this project is to begin a detailed study of the hydrogen content and isotopic compositions of H and O in calcium-aluminum rich inclusions (CAIs) and chondrules from primitive chondritic meteorites. CAIs are the oldest objects in chondritic meteorites, containing 26Mg derived from the decay of 26Al (half-life of 717,000 years) in the first few million years of solar system history; some chondrules also contain this signature but at much lower levels indicating that they are younger.
At some point early in the evolution of the solar system, huge amounts of water (likely in the form of ice) that condensed in the outer solar system is thought to have been transported into the inner solar system where Earth and the other rocky planets were forming. This would have changed the chemical conditions and O isotopic composition of the terrestrial planet region. By studying the amount of H2O, and H-O isotopes, in the oldest objects in chondrites, we hope to determine the precise timing and magnitude of this flux of water from the outer solar system into the planet-forming region where Earth was born.