Moonbeams and Elements

Moonbeams and Elements Written by G. Jeffrey Taylor Hawai'i Institute of Geophysics and Planetology To determine how a planetary body formed and evolved, we must determine the chemical compositions of distinctive geologic regions on it. It is never possible to obtain enough samples of a planet to do this job thoroughly, so planetary scientists have searched for ways of determining chemical compositions from orbit, which would allow chemical mapping of the entire surface. A team at the University of Hawai'i has developed a method to determine the amount of titanium and iron on the lunar surface from the amount of sunlight reflected at different wavelengths. Most recently, David Blewett, Paul Lucey, B. Ray Hawke (University of Hawai'i), and Bradley Jolliff (Washington University in St. Louis) have used Apollo rock samples to carefully calibrate the technique, allowing surprisingly accurate measurements of iron and titanium. These two elements are especially useful in understanding the origin and geological evolution of the Moon.