Rossman P. Irwin III Research Scientist Planetary Science Institute irwin @psi.edu

Most of my research projects focus on the Martian landscape, the processes that have shaped it over time, and the implications of surface features for a past warmer, wetter climate. These projects include analyses of data returned by robotic spacecraft, studies of Mars-analog features on Earth, planetary geologic mapping, and contributions to the selection of landing sites. I am also collaborating on a study of river channels formed by liquid hydrocarbons on Saturn's large moon, Titan.

Some current projects:

Hydrology of Early Mars

Many scientists have interpreted the Martian climate as "warm and wet" during the first 800 million years of its 4.5-billion-year history, but how warm, wet, and habitable was it? We have used the dimensions of ancient river channels on Mars to estimate the discharge of rivers, finding that the Martian landscape generated a centimeter per day of runoff at times. Studies of former lake basins, some of which overflowed, suggest that it did not rain often, however the wettest periods of time were still fairly dry by Earth's standards, perhaps like Utah or Nevada in the United States.

Erosion of the Martian Landscape

We are estimating the total amount of erosion at various locations across the Martian landscape, for insight into the long-term climate and water budget.

Development of Box Canyons on Earth and Mars

Many river valleys on Mars are long, narrow box canyons, with steep sidewalls and a cliff at the head. This type of canyon is less common on Earth, and it only forms in certain places. We are studying sites in the western United States and northern Chile to determine the roles of runoff, groundwater, rock layers, and fractures in forming box canyons.

Geologic Mapping of Mars

I am working with a team led by the U.S. Geological Survey to produce a new global geologic map of Mars, which will improve upon earlier maps based on Mariner 9 (1972) and Viking (1976-1980) data. I am also collaborating on a geologic map of Holden crater, which we proposed as a landing site for the upcoming Mars Science Laboratory rover (the site is currently on the short list of four finalists).

[Ross Irwin's CV]