Team Bios

Andy Rivkin

Principal Investigator

Andy Rivkin is a planetary astronomer at the Johns Hopkins University Applied Physics Laboratory in Laurel, MD, with his research focusing on the composition of asteroids. In particular, he is interested in those asteroids that have evidence of water or organic materials in them, detectable in their infrared reflectance spectrum. This pursuit has led to studies of asteroids from 1996 FG3, a near-Earth asteroid on which clay minerals has been found, to 24 Themis, an asteroid in the outer belt on which his team found water ice-- a first for asteroids. He has had particular interest in the dwarf planet Ceres, producing several papers in the past few years detailing its unusual composition and variation across its surface, as well as writing a focus paper for the Planetary Science Decadal Survey.

In addition to observational work, Andy has been active in the broader near-Earth object community, serving as a team member in several efforts to understand and report the impact hazard we face and how to lessen it, and leading a group reporting to NASA about the most important unknown factors related to human exploration of an asteroid.

Jeffrey Plescia

Deputy Principal Investigator

Jeffrey Plescia is a planetary scientist at The Johns Hopkins University Applied Physics Laboratory (APL), where he has worked since 2004. Before joining APL, he worked at the U.S. Geological Survey and the California Institute of Technology Jet Propulsion Laboratory (JPL). During his tenure at JPL, he served two temporary assignments to NASA Headquarters as the Planetary Geology and Geophysics Program Manager and as part of the Mars planning effort. He received his Ph.D. (1985) and M.S. (1981) in geophysics from the University of Southern California.

Jeffrey's research interests include the geology of Mars and the Moon, focusing on volcanic and tectonic activity, as well as impact cratering on the Moon and impact craters on the Earth. He was part of the International Continental Scientific Drilling Program-U.S. Geological Survey (ICDP-USGS) deep drilling project at the Chesapeake Bay Impact Crater and has conducted extensive field investigations at impact sites in the United States and Australia. Additionally, he has worked on the spectral signatures of hyperthermophile organism and siliceous sinter in Yellowstone National Park.

Jeffrey is currently working with the imaging experiment on the NASA Lunar Reconnaissance Orbiter.

Rachel Klima

Deputy Principal Investigator

Rachel Klima is a planetary geologist at the Johns Hopkins University Applied Physics Laboratory (APL). She obtained her undergraduate degree in Geophysical Sciences at the University of Chicago, and her PhD in Planetary Geology at Brown University, where she studied the relationship between crystal structure and the reflectance spectra of rock-forming minerals.

Rachel's research interests center on using reflectance spectroscopy to understand the thermal evolution of airless bodies in the solar system. During graduate school and a postdoc at Brown, she was involved with the Dawn mission to the asteroids Vesta and Ceres, as well as the Moon Mineralogy Mapper. At APL, she has continued her laboratory research and worked on the MESSENGER mission to Mercury. As part of the VORTICES team, she is working on spectral modeling of internally bound and surficially adsorbed water on nominally anhydrous minerals and meteorites.

Ben Bussey

Ben Bussey is a planetary scientist at The Johns Hopkins University Applied Physics Laboratory (APL) . He earned a B.A. in physics from Oxford University and a Ph.D. in planetary geology at University College London before moving to the United States. Before joining APL, Ben gained both science and mission experience while working at the Lunar and Planetary Institute in Houston, the European Space Agency, Northwestern University, and the University of Hawaii. He is currently the supervisor of APL's Planetary Exploration Group.

Ben's research concentrates on the remote sensing of the surfaces of planets, particularly the Moon. He has a particular interest in the lunar poles, producing the first quantitative illumination maps of the polar regions. He coauthored The Clementine Atlas of the Moon, the first atlas to map both the lunar near side and far side in a systematic manner.

In addition to being Principal Investigator (PI) of a NASA SSERVI team, he is also PI of the Mini-RF radar instrument on NASA's Lunar Reconnaissance Orbiter. This instrument, together with the Arecibo observatory, is currently acquiring unique bistatic radar data to search for polar ice deposits.

Ben enjoys planetary analogue field work and has been fortunate to have twice been part of the ANSMET (Antarctic Search for Meteorites) expedition to recover meteorites from the Antarctic glaciers.

David T. Blewett

David Blewett joined The Johns Hopkins University Applied Physics Laboratory as a member of the Senior Professional Staff in September 2007. Before that, he was a Principal Scientist at NovaSol (Innovative Technical Solutions, Inc.), a small employee-owned high-tech company in Honolulu, Hawaii of which he was a cofounder. His planetary research emphasizes remote sensing, geological analysis, and spectral algorithm development using data from planetary spacecraft including Mariner 10, Clementine, Galileo, Lunar Prospector, MESSENGER, and Dawn. He has been a Principal Investigator (PI) in NASA planetary research programs since 2002 and was named a MESSENGER Participating Scientist in 2007 and a Dawn at Vesta Participating Scientist in 2010. David has focused on geological and compositional analysis of ultraviolet-near infrared spectra and multispectral images, including study of space weathering trends on the Moon, Mercury, and Vesta. He served for three years as Co-chair of the MESSENGER Geology Discipline Group and a member of the PI's Science Steering Committee. He was an ANSMET (Antarctic Search for Meteorites) field party member during the 1988–1989 austral summer.

Andrew Dombard

Andrew Dombard's research centers on the study of the processes that shape the surfaces of the bodies in our solar system. Specifically, he is a geodynamicist who examines the response of an outer, mechanically stiff layer of a planet (known as the lithosphere) to various loads. The thickness of this lithosphere is tied directly to the thermal state of the body, which provides clues to its long-term evolution. The formation and evolution of a regolith is critical to such studies because this surface modulates the interior temperature structure.

M. Darby Dyar

Dr. M. Darby Dyar is the Kennedy-Schelkunoff Professor of Astronomy at Mount Holyoke College, where her research spans the inner solar system from Venus to Earth, the Moon, Mars, and meteorites. Her VORTICES research involves understanding the effect of mineralogy and crystal structure on H adsorption and the spectral properties of minerals under conditions found on airless bodies. Her research unites the fields of mineral spectroscopy and statistical analysis. She is coauthor of more than 190 papers. NASA and the National Science Foundation support her research on fundamentals and chemometric analyses of Mössbauer, XANES, Raman, and LIBS spectroscopies, as well as education research on the use of animations in teaching and the development of an award-winning textbook, Mineralogy and Optical Mineralogy. The latter has recently been published as an iBook by Apple Inc.

Jeffrey Gillis-Davis

Jeffrey Gillis-Davis specializes in using remote sensing data to study the geologic evolution and composition of the Moon, asteroids and Mercury. He also conducts laboratory space weathering experiments using a Nd-YAG laser. These experiments simulate micrometeorite impacts and how they modify the spectra and surface properties of materials on the surface of airless bodies.

Benjamin Greenhagen

Benjamin Greenhagen is a planetary scientist at Johns Hopkins Applied Physics Laboratory (APL). He earned a B.S. in Geophysics and a B.S. in Geology from the University of Minnesota, a M.S. in Earth and Planetary Science from Washington University in St. Louis, and a Ph.D. in Geology (Planetology) from the University of California, Los Angeles. Before joining APL, Ben enjoyed five years as a research scientist at the Jet Propulsion Laboratory, California Institute of Technology in Pasadena, CA.

Ben's research focuses on remote sensing of airless bodies. He is an expert in thermal emission spectroscopy and participates in both mission and laboratory experiments. Ben is the Deputy PI of the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer, a Co-I for the Lunar Flashlight cubesat, and has roles in numerous recent and ongoing mission and instrument proposals. Ben also manages APL's Simulated Airless Body Emission Laboratory (SABEL) that provides groundtruth for remote sensing datasets and enables fundamental investigations of compositional and thermophysical properties.

Kavan Hazeli

Kavan Hazeli is a postdoctoral research fellow at the Hopkins Extreme Materials Institute (HEMI) of The Johns Hopkins University. Kavan's research combines theoretical and experimental solid mechanics to study the link between microstructure and macroscopic properties of a variety of materials. He is specifically interested in multi-scale material characterization to develop a physics-based understanding of mechanisms that control plasticity, fatigue, and fracture.

Currently, he focuses on bridging microscale/nanoscale mechanics to macroscale behavior in order to understand and develop a constitutive relationship between thermal fatigue and the origin and evolution of regolith on airless bodies as well as the planetary-scale impact.

Karl Hibbitts

Karl Hibbitts is a planetary scientist at JHU-APL. He has a degree in physics from Cornell University (1989), and an MSc and PhD in Geology and Geophysics from the University of Hawaii (1999 and 2001, respectively). He was a post-doctoral researcher at the University of Washington and a research scientist the Planetary Science Institute before joining APL in 2005. His is interested in understanding the interactions between volatiles and regolith particles, and uses a combination of spacecraft data analysis and laboratory reflectance spectroscopy to characterize the spectral nature of these interactions. He is exploring the nature of adsorbed water on lunar materials and of cometary volatiles on outer planet icy satellite analog materials under relevant temperatures and pressures. He is also investigating through laboratory experiments, possible formation mechanisms of recurring slope linea on Mars. He was the deputy PI of two NASA balloon missions, BRRISON and BOPPS, to characterize the nature of carbon dioxide and water in comets and asteroids.

Dana Hurley

Dr. Dana Hurley is a planetary scientist at the Johns Hopkins University Applied Physics Laboratory (APL). She received a Ph.D. in Space Physics and Astronomy in 1999 from Rice Unviersity and a B. A. in Physics from The Johns Hopkins University (JHU) in 1993. She studies the atmospheres of airless bodies, the magnetic fields of non-magnetized planets, and the water cycles of desiccated moons. Thus she focuses on finding the interesting aspects of scant resources. Her contribution to VORTICES is through the Volatiles theme. Together with teammates, she will model processes acting to deliver water to coldtraps on the Moon and Near Earth Objects, especially the role of the solar wind as a source. Further, she will model the cold trap system for the stability and retention of water ice already in the cold traps. This builds on her work through the previous NASA Lunar Science Institute, as well as her participation in the Lunar Reconnaissance Orbiter (LRO) mission and Lunar Atmosphere and Dust Environment Explorer (LADEE) mission. Dr. Hurley is also a member of theDREAM2 SSERVI team.

Anton V. Kulchitsky

David Lawrence

David Lawrence has been at The Johns Hopkins University Applied Physics Laboratory since January 2008, and prior to that was a staff member at Los Alamos National Laboratory for 13 years. He obtained his education at Texas Christian University (B.S. physics, 1990) and at Washington University in St. Louis (Ph.D., physics, 1996). David carries out a variety of planetary, solar, and magnetospheric science projects using particle and nuclear spectroscopy techniques. He has experience in the design and development of spaceflight hardware, as well analysis and scientific interpretation of spaceflight data. He has participated in numerous spaceflight missions, including the NASA Lunar Prospector, Mars Odyssey, MESSENGER, and Dawn missions along with ESA's SMART-1 and multiple national security missions. For VORTICES, he is working to understand how previously gathered data from missions like Lunar Prospector can provide new information about lunar volatile compositions; he is also investigating what new measurements are needed for understanding lunar volatiles, and how these measurements can be obtained.

Richard S. Miller

Richard S. Miller is a professor of physics at the University of Alabama in Huntsville. Prior to this he held positions at the Los Alamos National Laboratory in New Mexico, as well as the Institute for the Study of Earth, Ocean, and Space (EOS) and the Department of Physics at the University of New Hampshire. He earned a B.S. in Physics from the University of California, Irvine; a M.S. in Physics from the Louisiana State University; and a Ph.D. in Physics from the University of New Hampshire. His research experience spans a range of disciplines, with an emphasis on particle and nuclear physics/astrophysics, instrumentation, and related applications. This includes evidence for surficial hydrogen within the Moon's Shackleton Crater and the first observation of neutrino emission from outside the solar system (Supernova 1987A). Other efforts include pioneering work using supernovae as stellar laboratories for neutrino studies, nuclear and very-high energy gamma ray astronomy, and cosmic-ray induced muon tomography for small solar system body investigations. For VORTICES, he is using advanced statistical analysis techniques, combined with new and archival gamma-ray and neutron observations, to understand lunar volatiles and plan for future investigations at the Moon. Dr. Miller has received a number of honors including the Los Alamos Distinguished Achievement Award, and the AAS Rossi Prize for High Energy Astrophysics.

K.T. Ramesh

K. T. Ramesh is the Alonzo G. Decker Jr. Professor of Science and Engineering at Johns Hopkins University. He is the Director of the Hopkins Extreme Materials Institute (HEMI), which advances the fundamental science associated with materials and structures under extreme conditions through the collaboration of academia, industry and external research organizations. His research interests are in high strain rate behavior and dynamic failure of materials, nanostructured materials, injury biomechanics and planetary scale impact problems. Prof. Ramesh received his doctorate from Brown University in 1987 and continued his education as a postdoctoral fellow at the University of California, San Diego. He joined the Department of Mechanical Engineering at Johns Hopkins in 1988 and served as Department Chair from 1999-2002. He has served as founding Director of the Hopkins Extreme Materials Institute (HEMI) since 2012. He has published one book (Nanomaterials: Mechanics and Mechanisms; Springer) and is an avid amateur astronomer.

Paul D. Spudis

Paul Spudis is a Senior Staff Scientist at the Lunar and Planetary Institute in Houston, Texas. He received his education at Arizona State University (B.S., 1976; Ph.D., 1982) and Brown University (Sc.M., 1977). His research focuses on the processes of impact and volcanism on the planets and studies of the requirements for sustainable human presence on the Moon. Paul was Deputy Leader of the Science Team for the Department of Defense Clementine mission to the Moon in 1994, the Principal Investigator of the Mini-SAR imaging radar experiment on India's Chandrayaan-1 mission in 2008–2009, and a team member of the Mini-RF imaging radar on NASA's Lunar Reconnaissance Orbiter mission (2009 to present). He was a member of the White House Synthesis Group in 1990–1991 as well as the President's Commission on the Implementation of U.S. Space Exploration Policy in 2004. He was presented with the NASA Distinguished Public Service Medal in 2004 and is the recipient of both the 2006 Von Karman Lectureship in Astronautics, awarded by the American Institute for Aeronautics and Astronautics, and a 2011 Space Pioneer Award from the National Space Society. Paul is the author or coauthor of more than 100 scientific papers and six books, including The Once and Future Moon, a book for the general public in the Smithsonian Library of the Solar System series, and (with Ben Bussey) The Clementine Atlas of the Moon, published by Cambridge University Press.

Additional information about Paul's work can be found at

Education and Public Outreach Team

M. Alexandra Matiella Novak

Dr. M. Alexandra Matiella Novak is a member of the Senior Professional Staff at Johns Hopkins University Applied Physics Laboratory. She joined the Space Department in 2010 as an Education and Public Outreach (E/PO) Specialist and transferred to a planetary scientist position within the Department in 2014. She received her Ph.D. (2008) and M.S. (2004) degrees in Geology from Michigan Technological University and her B.S. (2001) degree in Geology from the University of California, Los Angeles. She is currently splitting her time among leading the VORTICES E/PO program and conducting planetary geology research on the Moon and Venus, as well as mission planning for the CRISM instrument onboard the Mars Reconnaissance Orbiter. Alexandra enjoys applying Earth geology techniques to other planetary bodies, for example, using volcano cloud dispersion models developed for mitigating aviation hazards on Earth to study explosive volcanic material dispersion and deposition on Venus.

Christine Shupla

Christine Shupla supervises day-to-day operations for the Education department at the Lunar and Planetary Institute, and coordinates LPI's formal education efforts. She is the principal investigator for the Sustainable Trainer Engagement Program (STEP), and leads a number of teacher professional development programs. Ms. Shupla's bachelor's degree is in Astronomy, and she has a master's in Curriculum and Instruction. Prior to her work at LPI, Ms. Shupla spent approximately 15 years in the planetarium field, managing the planetarium and creating and presenting planetarium shows to approximately a million people.