INFRARED REMOTE SENSING OF VOLATILE COMPONENTS ON THE EARTH AND MOON

Abstract

This dissertation is focused on using infrared remote sensing to study volatiles on the Earth and Moon, including a strong hardware development component. The first project was aimed at developing light weight spectrometer for small satellites. In that work we build a 3 – 5 µm imaging interferometer, calibrated it, used it to collected data of the lava lake at Kilauea volcano, and analyzed a portion of the data with a radiative transfer model. We find that for high temperature targets, measurements in the 3 – 5 µm region can be acquired with high signal-to-noise ratios. The second two projects involve the study of water on the Moon using infrared astronomy. We investigate diurnal variations of hydration that was first detected on the Moon using orbiting infrared spectrometers. Analysis of spacecraft data, however, result in diametrically opposed results. Using new observations of the Moon with the NASA IRTF SpEX instrument we are able to overcome the fundamental limitations in the orbital data allowing us to resolve the diurnal variation controversies. Our improved data showed that the variation in hydration is real. The second astronomical project addresses a second fundamental problem. The spacecraft observations cannot tell the difference between the presence of water or hydroxyl. This has fundamental consequences for the behavior of volatiles on the Moon. However, we developed a new approach to detect the actual water molecule on the Moon using observations at 6 µm, based on how geologists detect H2O in samples in the lab using infrared spectroscopy. Observations at 6 µm are only possible from an airborne infrared observatory, we were granted time on the Stratospheric Observatory For Infrared Astronomy (SOFIA) to collect data of the Moon. Using data from SOFIA we report the first direct detection of the water molecule on the illuminated lunar surface.