Jeff Andrews-Hanna

After NASA’s 2001 Opportunity rover found rocks containing salt that formed in a watery environment on the planet’s surface roughly 3.7 billion years ago, the agency’s next objective was to try to understand more about the planet’s climate history.

This is where Mines Geophysics Assistant Professor Jeff Andrews-Hanna came into the picture. He used computer models of groundwater flow to understand Mars’ watery past. His models were able to predict where these salty deposits formed, and to explain what those rocks are telling us about the climate of Mars at the time.

Now he and his group are using models of the climate and groundwater of Mars to understand a mound of sediments in Gale crater, the target of the Curiosity rover that landed on the red planet in early August. Andrews-Hanna’s role is outlined in the Feb. 5, 2012 edition of The Chronicle of Higher Education: “Jeff is really state-of-the-art right now,” says Steven Squyres, a professor of astronomy at Cornell University and lead investigator of the Mars Opportunity rover mission. “We use water on Mars as a sort of proxy for habitability, for evidence that the planet once could have sustained life, so it’s really important. Jeff has brought a little physics into this work, and he is able to make predictions about water flow. We use those, in part, to guide our explorations. The rovers and the orbiters are the field geologists on Mars. Jeff is the theorist who brings their observations together.”

Top: Theoretical patterns of groundwater flow superimposed over a Mars Orbiter Laser Altimeter (MOLA) topographic map of Mars, centered on Meridiani Planum. Bottom: Layered rocks containing evaporitic sulfate minerals in Cape Verde, Meridiani Planum, taken by the Mars exploration rover, Opportunity. Source: NASA/JPL/Cornell

The nature of Mars’ early climate remains a controversial topic, as highlighted in a recent Nature News article featuring an interview with Andrews-Hanna. Debate continues between viewpoints of early Mars as a comparatively warm and wet place, or a cold and dry planet not very different from its present-day state. Research both at Mines and elsewhere will continue to push closer to an answer.

These days Andrews-Hanna has more and more help at Mines with those observations. His Planetary Geophysics Lab is attracting graduate students interested in researching the tectonic and geodynamic evolution of the red planet, its groundwater flow, its crustal structure, its moon, and the structure of the impact basins.

This is an edited version of an article first printed in Energy and the Earth 2012. More articles from that publication can be found at