Research

Research Interests:

Planetary Science

Geochemistry

Astrobiology

Machine Learning

Regolith in Jezero Crater:

Read more about this work in JGR: Planets!

"Mineralogically Diverse and Salt-Rich Regolith in Jezero Crater Characterized Using X-Ray Spectroscopy" (2025)

The surface of Mars is mostly covered with loose, granular material called regolith (AKA soil). Every landed mission since Viking has measured that soil has a nearly uniform composition at landing sites across the planet, suggesting a "global soil" unit. By studying regolith, we can learn about the processes that formed and subsequently altered it, which offer insights into what Mars looked like in the distant past. New instruments (such as PIXL, on NASA's Perseverance rover) allow us an unprecedented look at regolith. I am using PIXL to understand how the regolith forms, and what it can tell us about the past environments of Jezero Crater and Mars broadly.

Martian regolith, as seen by the WATSON instrument on the Perseverance Rover. Credit: NASA/JPL - Caltech.

Regolith: Resources and Hazards for Future Human Exploration

Watch me speak about regolith and future human exploration at the Lunar & Planetary Science Conference

"Regolith on the Rim of Jezero Crater and its Relevance to Human Exploration of Mars" (2026)

Shumway_LPSC2026_RegolithCraterRim.mp4

Soil, Salt, and Water on Mars:

Read more about this work in the Planetary Science Journal!
"Regolith Inhibits Salt and Ice Crystallization in Mg(ClO4)2 Brine, Implying More Persistent and Potentially Habitable Brines on Mars" (2023)

Water plays many fascinating roles on Mars: it can alter the surface chemically and physically, and potentially even support life! But today, liquid water is extremely rare on Mars. Freezing temperatures and low pressure make pure liquid water impossible. Even in the face of these extreme conditions, liquid water could persist on Mars in the form of salty solutions known as brines. These brines form when salts in the soil absorb water vapor from the air and dissolve. Once formed, brines can stay liquid - even at extremely low temperatures - because salty water freezes at a lower temperature than pure water. My research strives to understand these processes and how water, salt, and soil interact to allow water to exist on Mars today.

Unfortunately, I can't go to Mars and investigate brines in situ. Instead, I study how Martian brines behave by recreating a little piece of Mars in the lab. Using salts and simulated Martian dirt, my experiments reveal the thermodynamic properties of cold brines in soil. How much water is available in these brines? Can they remain liquid despite Mars' cold, arid environment? Could they possibly even support life? Through experiments and modelling, I seek to answer these questions and more!

A laboratory analog of Martian regolith mixed with brine. Credit: Andrew Shumway

Machine Learning & Artificial Intelligence in Planetary Science:

Planetary science is rapidly evolving from a data-poor to a data-rich field. With an increasing number of successful planetary missions returning huge volumes of data to Earth each day, new techniques are needed to parse through these massive, growing datasets. Existing data science and machine learning techniques can be extremely helpful for teasing patterns and trends out of these large datasets, but such techniques are slow to be adopted by many planetary scientists. I'm interested in applying these techniques to find hidden discoveries in existing planetary datasets.

Examples of various clustering techniques. Credit: scikit-learn.

Planetary Protection:

As our exploration of the Solar System accelerates, so too do concerns about planetary protection. Planetary protection seeks to minimize the harms of biological cross-contamination between Earth and other habitable worlds. It is therefore crucial to fully characterize potentially habitable environments on Mars, both for their astrobiological potential and to ensure such environments are protected from terrestrial biology.

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