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. To apply for a postdoc in Mars geochemistry or quantitative imaging spectroscopy (especially ices or Earth science), fill out the application here.


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.
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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

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.

Kevin Roback

Kevin Roback
Graduate Student
Kevin Roback grew up in Michigan and got his bachelor’s in Earth and Environmental Science at the University of Michigan-Ann Arbor. He is interested in various sorts of planetary surface processes and currently studies active sand transport on Mars, as well as factors driving spatial patterns of landsliding on Mars.

Cecilia Sanders

Cecilia Sanders
Graduate Student
Cecilia Sanders is a planetary science graduate student. She studies biosignatures - understanding how living things affect their environments, and how those effects might be recorded in the rock record, oceans, or atmosphere of a planet. She does this by culturing microbes in the lab and by going out in the world to understand paleoenvironments and biosignatures in the deep history of the Earth, interrogating samples from all these sources using Caltech’s incredible suite of analytical instruments. In addition to her research, Cecilia is an avid artist/illustrator and volunteers her time teaching elementary school science classes.

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.

Undergraduate Students

Molly Crotteau

Molly Crotteau
Undergraduate Student '21
Molly Crotteau is an undergraduate at Caltech majoring in geochemistry and minoring in environmental science. Molly is interested in the ways in which spectroscopy can used to quantify and track hydration in the oceanic crust. She is currently using imaging spectroscopy to study hydration and alteration in the ICDP Oman Drilling Project cores.

Jay Dickson

Marcos Perez
Undergraduate Student '23
Marcos Perez is sophomore at Caltech majoring in planetary science with a minor in astrophysics. He is an undergraduate research fellow with the Ehlmann Research Group and the Lunar Trailblazer NASA mission, which will orbit the Moon 2025 to study water ice on the Lunar surface. His current research uses multiple remote sensing datasets to map water ice on the Moon's surface and statistically analyze its spatial distribution.


  • 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 Postdoc on MSL Chemcam and Mars 2020 Supercam team, Museum of Natural History, Paris
  • Dr. Peter Martin (PhD 2020) –now Postdoctoral Researcher, University of Colorado Boulder (starting March 2020)
  • 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 NASA Postdoctoral Program Fellow at JPL
  • Dr. Jennifer Buz (PhD 2018) –now Postdoctoral Researcher, Northern Arizona University
  • 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 Maître de conferences at Univ Paris-Sud

Former Summer Interns

  • Ethan Ordentlich (Caltech ’21; co-advised with Rebecca Greenberger)
  • Lauren Suezaki (Caltech ’21)
  • Elise Cutts (Caltech ’19; now a Fulbright scholar in Denmark)
  • Geraint Northwood-Smith (Cambridge ’17; co-advised with Abigail Fraeman)
  • Caue Borlina (U. Michigan ’16; now graduate student at MIT, planetary sciences)
  • Eyjolfur Gundmundsson (U. Reykjavik ’13; now graduate student at U Chicago, medical physics)
  • Bryne Hadnott (WUSTL ’13; now graduate student at Cornell, geological sciences)
  • Cecilia Sanders (Harvard ’16; now graduate student at Caltech, planetary science; co-advised with Glenn Sellar (JPL))
  • David Smith (Troy High School, ’13)
  • Jade Wang (Caltech ’15)