Spring

In the spring newsletter, we reported Michelle Thompson as the recipient of the 2014 Shandel (now Curson) Travel Scholarship. Michelle is beginning her fourth year as a graduate student working with Assistant Professor Tom Zega. She used the travel support to attend the annual Microscopy and Microanalysis Conference in Hartford, Connecticut, August 2014, and to present her work as a talk titled, “Electron Energy‐Loss Spectroscopy of Iron Nanoparticles in Lunar Soil using an Aberration-­Corrected Scanning Transmission Electron Microscope.” Michelle describes the experience as a "unique opportunity to present my work to both the planetary science community and the community of microscopy experts."  Michelle's paper was selected for a Presidential Scholar award. 

Michelle's dissertation focuses on the effects of space weathering processes and how they manifest themselves in soils on airless bodies. She studies the effects of space weathering in samples from the Moon and near-Earth asteroid Itokawa. The lunar samples used in her analysis were returned from the Moon by the Apollo missions and the samples from Itokawa were collected by the Japanese Aerospace Exploration Agency’s Hayabusa mission.

The effects of space weathering are concentrated in the outer one hundred nanometers of soil grain surfaces. In order to study these features at such a fine scale, Michelle uses an instrument called a transmission electron microscope (TEM), which allows her to get crystal structure and chemical information from samples at very small scales—the perfect tool for providing insight into space weathering processes. Among the space weathering features Michelle has been analyzing are iron nanoparticles in lunar soil, with each particle measuring only a few nanometers in size. These nanoparticles are produced through various space weathering processes and are responsible for changing the optical properties of the surface soils. Until recent advances in electron microscopy, scientists were unable to study the oxidation state Fe within individual particles. By using a state-of-the-art TEM, our study suggests these nanoparticles are not composed entirely of metallic iron, but a mixture of oxidation states. This has important implications for the nature of space-weathering processes on the surfaces of airless bodies.

The Shirley D. Curson Education Plus Fund in Planetary Sciences and LPL (formerly the Shandel Education Plus Fund) was established by Shirley Curson, a generous donor and friend of LPL, for the purpose of supporting travel expenses outside the state of Arizona during summer break. The award is open to students in the Department of Planetary Sciences and Lunar and Planetary Laboratory who propose to fund study, museum visits, special exhibits, seminars, instruction, competitions, research and other endeavors that are beyond those provided by the normal campus environment and are not part of the student’s regular curriculum during the recipient’s school year.

Dr. Gilda Ballester has been named a Senior Research Scientist in the Department of Planetary Sciences/Lunar and Planetary Laboratory. Gilda has been an Associate Staff Scientist at LPL since 2000. Before coming to Tucson, she conducted her research at the University of Michigan as an Associate Research Scientist in the Department of Atmospheric, Oceanic and Space Sciences, Space Physics Research Laboratory. Gilda earned her Ph.D. in Physics (Astronomy minor) at Johns Hopkins University. Her research interests include characterization of exoplanets with transit observations at UV, optical and near-IR wavelengths with the Hubble Space Telescope and through collaborative ground-based observations. This research focuses on the properties of both the upper and lower atmospheres of hot Jupiters and low-density super Earths, and of magnetospheric interactions on these exoplanets. Her early research interests included Io’s atmosphere and plasma torus, and on the upper atmospheres, auroras and magnetospheric interactions of Jupiter, Saturn and Uranus with both imaging and spectroscopy.

Congratulations to Juan M. Lora, recipient of the 2014 Gerard P. Kuiper Memorial Award.

Juan Lora earned his B.S. in Astronomy (magna cum laude) from the University of Southern California in 2009. His research objective as a graduate student at LPL has been to understand the dynamics and history of Titan’s atmosphere, the only other body in our solar system with an active “hydrological” cycle, and to develop the necessary tools for understanding the atmospheres of extra-solar, potentially “Earth-like” planets. By using his adaptation of an ‘Earth-centric’ coupled general circulation model for application to Titan, he efficiently achieved the necessary code modifications and now has a working model of the Titan atmosphere. His simulations will allow an integrated assessment of the diverse observations of Titan, ranging from the polar methane lakes to the longitudinal dunes seen at low latitudes.

As a graduate student in the Department of Planetary Sciences, Lora has already achieved excellence with his research into the patterns of insolation and the seasonal variability of cloudiness and temperature throughout Titan’s troposphere. His analysis of Titan’s troposphere is both insightful and creative and was recently published in Icarus (Lora et al., 2011). This paper clearly shows that previous modeling efforts employed unphysical parameterizations of the insolation and that the conclusions drawn from those simulations about Titan’s wind and temperature profiles are likely erroneous. Lora’s most recent work, exploring the orbitally-forced variability of the lake locations on Titan using a modern general circulation model, clearly shows his increased expertise and technical skill, even considering the already high level of achievement present in his early work.

Lora is the recipient of a NASA Earth and Space Science Fellowship (NESSF) for 2012-2014. He will defend his dissertation on "Radiation and Dynamics in Titan's Atmosphere: Investigations of Titan's Present and Past Climate" in 2014. Associate Professor Joellen Russell is Lora's advisor.