Ehlmann is in the Pathfinder Program, an intensive environmental-studies curriculum directed by Raymond E. Arvidson, Ph.D., the James S. McDonnell Distinguished University Professor and chair of the earth and planetary sciences department in Arts & Sciences. Ehlmann is also a Compton Fellow and Fossett Fellow.

"Bethany is typical of Pathfinder students as a whole," Arvidson said. "It's tough to get into the NASA Ames Astrobiology Summer Academy, tough for anyone, but really tough for a sophomore. It's nice to work with enthusiastic, brilliant young students."

The astrobiology academy is a 10-week summer internship at NASA Ames Research Center in Mountain View, Calif. During the summer, Ehlmann will work on a research project, "The Potential for Liquid Water on Mars," studying perennial spring systems in the Canadian High Arctic with NASA scientist Chris McKay.

Each of the 12 academy attendees is assigned to a project dealing with climate research, life and geology of extreme environments (for instance, space, polar regions, deserts), or the evolution of the solar system. The goal of the academy is to encourage participants to become leaders in the space science field and also to foster a working knowledge of NASA by meeting with research scientists, mission planners and industry leaders in the aerospace field.

Ehlmann was chosen for her academic record, her interest in the research projects being offered and her interest in working at NASA on Mars research in the future, not to mention her experience working with Arvidson, who has been a NASA scientist since the 1970s.

Ehlmann has been working to develop a predictive hydrologic model of Lake Waiau, a small lake in the glacial-volcanic landscape of the summit of Mauna Kea, Hawaii. Using data from a nearby weather station, D/H (deuterium/hydrogen) and 18 oxygen/16 oxygen isotope ratio measurements, lake level measurements, and topographic information, she has constructed a computer model that gives daily predicted values for lake level and lake isotope ratios.

"I'm also interested in exploration of the surface of Mars using rover technology, especially using traverse data to better characterize the terrain," Ehlmann said. "Using position and suspension data from the Sojourner Rover on the 1997 Mars Pathfinder mission, I've been able to localize each of the six rover wheels in a 3-D lander referenced coordinate system. Potentially, such data can be used to determine the fractal dimension of the landing site's microtopography, calibrate orbital data indicating landing-site roughness, and derive the soil physical properties."

Last year over spring break, Ehlmann and her Pathfinder colleagues spent four days in the Mojave Desert area and one day in Death Valley. In the Mojave Desert, they examined Lake Manix, Afton Canyon, Devil's Playground, Kelso dunes, the Cima Volcanic Field, Soda and Silver Lakes, Cronese Lake and the Cima Dune (Teutonia Peak).

In Death Valley, they examined lake deposits and alluvial fans. In all cases, the focus was on evidence for the paleoclimatic history of the area during the past million years. The research was conducted within the context of policy issues associated with the California Desert Protection Act of 1994.