Sesquinaries, Magnetics and Atmospheres: Studies of the Terrestrial Moons and Exoplaets
- Author(s): Nayak, Michael
- Advisor(s): Garrick-Bethell, Ian
- et al.
The surface brightness of Deimos, groove patterns on Phobos, crustal magnetic anomalies on the Moon and the composition of exoplanet atmospheres represent some of the most interesting and puzzling questions in planetary science. Why is Deimos significantly brighter and smoother than its partner moon Phobos? What is the origin of the crater chain “grooves” on Phobos? Are the magnetic anomalies in the lunar South Pole-Aitken basin a remnant of the basin’s formation, or do they owe their existence to a primordial period of lunar dynamo activity? And finally, as visible wavelength telescopes are designed and tested for space-based exoplanet detections, can we use observed albedo spectra to determine radius, gravity, cloud pressure heights and atmospheric compositions for these planets? I use dynamical modeling, magnetic inversions and Markov Chain Monte Carlo retrievals to address these questions. Major findings include 1) the likelihood of isotropic redistribution of reaccreted ejected material on Deimos, 2) the creation of hemispherical catenae from the creation of primary craters on Phobos, which match the locations and geomorphology of several existing grooves well, 3) the first directional magnetic survey of South Pole-Aitken basin anomalies, and a larger than expected diversity in recovered paleopole directions, and 4) the critical importance of considering the effects of planet phase in exoplanet atmosphere retrievals; changing planet phase, when combined with low signal-to-noise observations, can cause several orders of magnitude of uncertainty in atmospheric methane composition and cloud pressure height, among others.