A Cool Compound

“We really want to know as much as we can about the ocean underneath the ice, because anywhere with liquid water is a good place to look for life,” says Tomlinson. But without direct access to that ocean, scientists must instead use clues from the ice on the surface.”

“It’s incredibly difficult to land on another planet or moon, so for these locations far out in the solar system we can only understand them from what we see from orbit,” she says. The goal is to understand the physical properties of various types of ice—made from water as well as nitrogen, carbon dioxide, methane, and other materials prevalent in the cold reaches of space—so scientists can develop better-informed models.

Tomlinson and research scientist Jacob Buffo grow the samples in Dartmouth’s Ice Research Lab in collaboration with lab manager Andrii Murdza Th’20 and Tomlinson’s advisor, Professor Colin Meyer.

“Each of the ices is made of different mixtures of chemicals,” she says, “which affect the way the water freezes and can change a lot of properties of the ice that are relevant for geophysics and remote sensing.” She’s currently testing how different types and amounts of salts in water affect the internal structure and strength when frozen.

Buffo is leading another ice project with funding from the Planetary Society’s Science and Technology Empowered by the Public (STEP) program. “The grant will fund field work to study hypersaline lake systems in central British Columbia, Canada, for me and six co-investigators across six different institutions,” he says. The lakes are analogous to what may exist on other planets and moons and can provide insights into what is possible in those conditions.

The salt in Earth’s oceans is mostly table salt, which is not as prevalent in the salts found on Mars and in the subsurface oceans of Jupiter’s Europa and Saturn’s Enceladus. Buffo will study lakes containing sodium carbonate, sodium sulfate, and magnesium sulfate, which more closely mirror the compositions of these alien oceans.

In year one, the team will carry out field investigations to create multiscale profiles of the ice-brine-sediment systems of five lakes in the Cariboo Plateau.

In year two, researchers will use what they have learned to predict what they will find at two additional unexplored lakes, carrying out a simulated planetary mission to evaluate their methodology and science.