The Ehlmann lab spans the options in Caltech’s Geological & Planetary Sciences Division.

Exceptional candidates for postdoctoral fellowship programs or the Caltech Ph.D. program should consider applying, especially if research interests span multiple faculty. Note that many postdoctoral prize fellowships have early fall deadlines and our Division prize fellowship is due December 1. Prof. Ehlmann also works with JPL scientists to co-advise NASA postdoctoral program applicants. Late December/early January is the deadline for graduate admissions (see Caltech site for details). Broadly, we are looking for graduate students and postdoctoral scholars with interests in (1) spectroscopy of geologic materials, including rocks, ices, organics (lab, mission data, modeling), (2) geological history and history of water and hydrous mineral formation on Mars, Earth, Venus, the Moon, asteroids, or Ocean Worlds. Specific projects seeking personnel include mineralogy/geochemistry from MSL/Mars-2020 datasets, lunar water and compositional remote sensing in preparation for Lunar Trailblazer, machine learning/computational approaches to remote compositional analysis with hyperspectral data, and land use/land cover change in California with hyperspectral remote sensing.


Bethany Ehlmann

Professor Bethany Ehlmann
Professor of Planetary Science
Professor Ehlmann's research focuses on the mineralogy and chemistry of planetary surfaces, remote sensing techniques and instruments, astrobiology, and science policy and outreach.
Biography >>


Jay Dickson

Jay Dickson
Research Scientist in Image Processing
In his capacity as an imaging scientist in charge of Caltech's Bruce Murray Lab for Planetary Visualization, the Ehlmann group works extensively with Jay Dickson.

Rebecca Greenberger

Dr. Rebecca Greenberger
Lab Manager and Research Scientist
Dr. Rebecca Greenberger (she/her/hers) received her PhD in 2015 from Brown University, joined the Ehlmann group as a NASA Postdoctoral Program Fellow at JPL for two years, and has been the group’s lab manager and a research scientist at Caltech since 2017. She is interested in the use of imaging spectroscopy and other spectroscopic techniques in the field and laboratory to better understand Earth and other planets. Her current projects include investigation of deep hydrothermal circulation in Earth's ocean crust and the products of serpentinization, both using micro-imaging spectroscopy.

Jasper Miura

Jasper Miura
Research Technician Associate
Jasper Miura (he/him) joined the Ehlmann lab after completing his B.Sc. in inorganic geochemistry at Brown University in 2019. His current project uses imaging spectroscopy to study Martian meteorite spectral diversity. His work also consists of brand design, web design, and general graphic design for the Lunar Trailblazer mission.

Postdoctoral Scholars

Andrew Annex

Dr. Andrew Annex
Postdoctoral Scholar
Dr. Andrew Annex joined the Ehlmann lab after receiving his Ph.D. in Earth and Planetary Sciences from Johns Hopkins University in January 2022. His dissertation was on the regional sedimentary record of Arabia Terra, Mars. His interests include surface processes, remote sensing, and the applications of artificial intelligence towards the exploration of Mars and ocean worlds.

Graduate Students

Samantha Baker

Samantha Baker
Graduate Student
Samantha Baker (she/her/hers) graduated from the University of Chicago in 2021 with a B.S. in Geophysical Sciences. In her current research, she uses spectral data to understand the aqueous history of Mars through the examination of silicate weathering. Her broad research interests include exploring planetary surface processes through the lenses of geochemistry and geomorphology.

Oak Kanine

Oak Kanine
Graduate Student
Oak (they/them/theirs) graduated from Dartmouth College in [the fateful year of] 2020 with A.B.s in Earth Science and Native American Studies. Their broad research interests include Martian paleoclimate; the development of a generalized model of planetary evolution through comparative planetary science; and questions of habitability. Their current work focuses on Martian geomorphology and the history of liquid water on Mars, as well as Martian landscape evolution through dry processes such as rockfall.

Samantha Baker

Abigail Keebler
Graduate Student
Abigail Keebler grew up in southeastern Pennsylvania and graduated from West Chester University of Pennsylvania in 2021 with her B.S. in Geoscience-Geology and minors in Physics and Mathematics. Abigail is interested in planetary surface processes on terrestrial planets and rocky moons. Currently, she is using spectroscopy to constrain the mineralogy of atmospheric dust on Earth.

Jessica Mueller

Jessica Mueller
Graduate Student
Jessica grew up in Nampa, Idaho, and graduated from Boise State University with a B.S. in Geosciences in 2021. She is broadly interested in the isotopic and mineral evolution of the solar system. In her current research, she is creating a robust framework of spectral data from calcium-aluminum-rich inclusions (CAIs) that will better inform the interpretations of remote sensing data.

Yu Yu Phua

Yu Yu Phua
Graduate Student
Yu Yu Phua graduated from the University of Tokyo in 2021 with a M.S. in Materials Science. She is interested in studying planetary chemistry involving H2O through laboratory experiments. Currently, she is working on the detection threshold for H2O spectral signatures.

Sergio Parra

Sergio Parra
Graduate Student
Sergio Parra is an Atlanta-native and earned his B.S. in Chemical and Biomolecular Engineering from the Georgia Institute of Technology, alongside a minor in Earth and Atmospheric Sciences. His current work centers on characterizing the aqueous alteration of carbonaceous chondrites using SWIR spectroscopy. His broad research interests include ancient habitable environments, the origin of life, and extant microbial communities in the deep biosphere.


  • Brandon Rasmussen (MS 2020) –now working at Planet
  • Dr. Eva Scheller (PhD 2022) –now 51 Pegasi b Postdoctoral Fellow at MIT
  • Dr. Kevin Roback (PhD 2021) –now Research Staff Member, Institute for Defense Analyses
  • Dr. Nathan Stein (PhD 2020) –now Senior Machine Learning Engineer, Rebellion Defense
  • Dr. Ellen Leask (PhD 2020) –now Postdoctoral Scholar, Applied Physics Lab
  • Dr. William Rapin (postdoc 2017-2020) –now CNRS Research Scientist, Université de Toulouse
  • Dr. Peter Martin (PhD 2020) –now Postdoctoral Researcher, University of Colorado Boulder
  • Dr. Dana Anderson (PhD 2020) –now Postdoctoral Fellow, University of Virginia
  • Dr. Valerie Fox (postdoc 2017-2019) –now Postdoctoral Researcher, University of Minnesota
  • Dr. Nancy Thomas (PhD 2019) –now on Black Sky Image Processing Team at Spaceflight Industries
  • Dr. Elena Amador (postdoc 2017-2019) –now Systems Engineer on MSL Science Operations Team at JPL
  • Dr. Peter Buhler (PhD 2018) –now Research Scientist, Planetary Science Institute
  • Dr. Jennifer Buz (PhD 2018) –now Remote Sensing Scientist, Orbital Sidekick
  • Dr. Daven Quinn (PhD 2018) –now Research Scientist, University of Wisconsin-Madison
  • Dr. Mathieu Lapôtre (PhD 2017) –now Assistant Professor at Stanford University
  • Dr. Lu Pan (PhD 2017) –now Postdoc, Centre for Star and Planet Formation, University of Copenhagen; Assistant Professor of Planetary Science, University of Science and Technology of China, starting in 2023
  • Dr. Abigail Fraeman (postdoc 2014-2016) –now Research Scientist at JPL
  • Dr. Christopher Edwards (postdoc 2012-2015) –now Associate Professor at Northern Arizona University
  • Dr. Cedric Pilorget (postdoc 2012-2014) –now Research Faculty at IAS-Orsay

Current and Former Interns

  • Claire Blaske (Arizona State University ’23; co-advised with Rebecca Greenberger)
  • Amy Wang (Cornell ’23; co-advised with Rebecca Greenberger)
  • Sahil Azad (Caltech ’25; co-advised with Rebecca Greenberger)
  • Andy Sun (Caltech ’24)
  • Riley Tam (Caltech ’24; co-advised with Jay Dickson)
  • Marcos Perez (Caltech ’23)
  • Molly Crotteau (Caltech ’21; co-advised with Rebecca Greenberger; now graduate student at UC Santa Barbara)
  • Ethan Ordentlich (Caltech ’21; co-advised with Rebecca Greenberger)
  • Lauren Suezaki (Caltech ’21, now electrical engineer at Northrop Grumman)
  • Elise Cutts (Caltech ’19; now American Association for the Advancement of Science Mass Media Fellow)
  • Geraint Northwood-Smith (Cambridge ’17; co-advised with Abigail Fraeman; now graduate student at Imperial College London, planetary science)
  • Cauê Borlina (U. Michigan ’16; now Postdoctoral Fellow at Johns Hopkins University)
  • Eyjolfur Gudmundsson (U. Reykjavik ’13; now research fellow at University College London, medical image computing)
  • Bryne Hadnott (Washington University in St. Louis ’13; now Data Curator and Storyteller at Stanford University)
  • Cecilia Sanders (Harvard ’16; co-advised with Glenn Sellar (JPL); now graduate student at Caltech, geology)
  • David Smith (Troy High School, ’13)
  • Jade Wang (Caltech ’15)