A University of Iowa research team has won a grant to study the composition and climatic origins of a 2,500-mile-long canyon on Mars. 

Valles Marineris is the largest known canyon system in the solar system, spanning approximately one-fifth of the red planet’s circumference.

Planetary scientists want to learn more about the immense canyon because it offers a more than 4-mile-deep look into Mars' interior and geologic history. The detailed look into Mars’ interior contrasts with data obtained from satellites and orbiting spacecraft that can peer only a few inches below the Martian surface.

Valerie Payré, assistant professor in the School of Earth, Environment, and Sustainability and the project’s principal investigator, said the research could reveal how Valles Marineris formed and evolved. 

It also could yield clues into the past climate on Mars, which some 3–4 billion years ago was thought to have been warm and wet and then became arid and dry when it lost its magnetic field and most of its atmosphere and water dissipated into space.

The researchers will take data from three orbiting spacecraft to search for minerals and geological features on the floor of Valles Marineris that have high thermal inertia properties, meaning they are highly resistant to changes in temperature. Locating high thermal inertia regions in Valles Marineris and studying the composition of rocks and minerals there could reveal the geological processes that shaped Mars.

Protiti Roy, a graduate student in the School of Earth, Environment, and Sustainability and an investigator on the project, says researchers look for iron-rich clays, which form when the minerals olivine and pyroxene react with water. Finding iron-rich clays could be evidence of past water activity and could help scientists reconstruct Mars’ ancient environment.

Payré says the research will help guide future missions on Mars by improving scientists' understanding of the canyon’s geology. She is partnering with NASA’s Jet Propulsion Lab and the French Space Agency on a proposal to fly a helicopter on the floor of the canyon to collect more detailed observations. 

“We’d be able to see ancient materials and what the crust of Mars looked like 4.5 billion years ago. That’s something we've never really observed on Mars,” Payré says. “Protiti’s work is telling us where to go.” 

The two-year grant from NASA is for $100,000.