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

Exceptional candidates for the 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). January 1 is the deadline for graduate admissions. We are looking for graduate students and postdoctoral scholars with interests in (1) spectroscopy of geologic materials, including rocks, ices, organics (labwork remote sensing data analysis, radiative transfer modeling), (2) geology and hydrous mineral formation with an interest in Mars, Earth, or Ocean Worlds; (3) Earth hyperspectral remote sensing data collection and analysis for rock/soil composition (EMIT mission), drill core analysis (Oman Drilling project), and/or soil/vegetation studies combining field and remote sensing data. Interested candidates should send a CV and short description of interests.


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
Rebecca Greenberger received her PhD in 2015 from Brown University in Geological Sciences. She then joined the Ehlmann research group as a NASA Postdoctoral Program Fellow at JPL for two years and became the group’s lab manager and a research scientist at Caltech in July 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.

Jasper Miura

Jasper Miura
Research Technician Assistant
Jasper Miura joined the Ehlmann lab after completing his B.Sc. in inorganic geochemistry at Brown University in 2019. For his undergraduate thesis, he experimentally synthesized textures found in meteorites to constrain igneous processes in the Martian crust and mantle. Currently, he is combining his experience in planetary petrology with his interests in remote sensing and data visualization, using imaging spectroscopy to study Martian meteorites.

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.

Melanie Kanine

Melanie Kanine
Graduate Student
Melanie (they/them/theirs, she/her/hers) 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.

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

Brandon Rasmussen
Graduate Student
Brandon Rasmussen grew up in the foothills of the Sierra Nevada Mountains in Reno, Nevada. He completed dual B.S. degrees in Geophysics and Geology along with minors in Mathematics and Physics in 2017 at University of Nevada, Reno, before taking two years to work in various industries all utilizing remote sensing. Brandon is interested in advanced processing of spectral imagery to better understand geological processes on Earth and other planetary bodies. He is currently working on a global hydrothermal mineral inventory of Mars.

Eva Scheller

Eva Scheller
Graduate Student
Eva Scheller got her B.Sc. in geology-geoscience from University of Copenhagen. Her current projects include composition and impact deformation of Noachian basement on Mars and formation of ikaite and dendritic textures in tufa in alkaline lakes. Her research interests include Martian geology, paleoclimatology, ancient habitable environments, and low-temperature geochemistry.


  • Dr. Kevin Roback (PhD 2021) –now Research Staff Member, Institute for Defense Analyses
  • Dr. Nathan Stein (PhD 2020) –now Postdoctoral Scholar, Caltech
  • 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
  • Dr. Abigail Fraeman (postdoc 2014-2016) –now Research Scientist at JPL
  • Dr. Christopher Edwards (postdoc 2012-2015) –now Assistant Professor at Northern Arizona University
  • Dr. Cedric Pilorget (postdoc 2012-2014) –now Research Faculty at IAS-Orsay

Current and Former Interns

  • 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)
  • Elise Cutts (Caltech ’19; now graduate student at Harvard, geobiology)
  • 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 graduate student at MIT, planetary sciences)
  • Eyjolfur Gudmundsson (U. Reykjavik ’13; now research fellow at University College London, medical image computing)
  • Bryne Hadnott (WUSTL ’13; now Research Scientist at BlackSky imaging)
  • 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)