Alien oceans

When Daniel Abdulah learned to write, his earliest scribbles included the names of planets, in order, alongside little drawings of each one. That early fascination with worlds beyond Earth never really faded. The child’s imagination matured into a passion for research into the physics of alien oceans, particularly those hidden beneath the icy shells of Saturn’s and Jupiter’s moons.

Abdulah, now a graduate student at the Massachusetts Institute of Technology, works at the intersection of fluid dynamics, planetary science and high-performance computing. His research focuses on how subsurface oceans interact with the overlying ice crusts of moons such as Enceladus, one of Saturn’s 146 known satellites. His work explores how gravity waves in those oceans may generate the distinctive fissures known as tiger stripes, where massive plumes of water erupt hundreds of miles into space.

“We’re interested in how the ice and the ocean underneath communicate because, while the ocean is the part that might host life, the ice is the part we can actually observe,” Abdulah says.

Working with planetary scientist Wanying Kang’s group and supported by a Department of Energy Computational Science Graduate Fellowship (DOE CSGF), Abdulah uses the MIT General Circulation Model to translate the Saturnian moon’s ocean physics into a three-dimensional matrix of cells, each one governed by equations describing pressure, temperature, salinity and velocity.

“Running these simulations feels like being able to control the weather,” he says. “You can set the temperature to whatever you like or initialize a field with turbulence just by flipping a flag from true to false. Or you could ask bigger questions like what would happen if the Earth’s continents were all lumped together, or the ocean was 10 times deeper.”

Abdulah’s path to planetary science was itself not immune to turbulence. He has a knack for moving fluidly among disciplines — working in an MIT neuroscience lab while in high school, exploring particle physics and telescope design as a Harvard University undergraduate, completing concurrent bachelor’s and master’s degrees in mathematics in just four years. His thesis research, steeped in pure math, focused on algebraic graph theory, exploring how information propagates through symmetric networks called Cayley graphs.

The shift from theory to planetary science came through an internship at NASA’s Jet Propulsion Laboratory during the COVID-19 pandemic. With physical labs closed, Abdulah joined a remote project modeling the oceans of Europa, an icy moon of Jupiter. The experience reawakened his childhood interest in space and set the trajectory for his graduate research, where he explores how fluid motion pertains to utterly non-Earth-like conditions. His simulations suggest that vertically propagating inertia-gravity waves in Enceladus’ ocean may transfer energy upward, shaping the moon’s surface fractures and perhaps maintaining the geysers observed by the Cassini spacecraft.

The insights from such models do more than satisfy curiosity. They can help prioritize what measurements spacecraft will glean on future missions.

Through the DOE CSGF, Abdulah completed two laboratory practicums, experiences he credits for shaping his computational fluency. At Oak Ridge National Laboratory, he investigated numerical algorithms for time-stepping fluid solvers. “It was a really cool mix of computer-science skills that I’m glad I learned in a research setting. If I’d taken a class for each programming language we used, that would’ve taken forever. Instead, I got to use three languages in one summer for a project with a tangible goal.”

His second practicum, at the National Renewable Energy Laboratory, explored molecular and fluid-dynamic simulations of crystal formation for next-generation solar panels. “As much as I love planetary science, I wanted to work on something with a more immediate impact. It’s great when you find something mathematically interesting that people can actually use.”

The project gave him an appreciation for modeling at vastly different scales. “In planetary simulations, I ignore viscosity and diffusion; at that scale, they’re negligible. But for crystal growth, those processes are everything. Seeing both sides really rounded out my perspective.”

Despite the technical nature of his work, Abdulah is drawn to its aesthetic and philosophical dimensions. His writing often links the mathematics of turbulence to poetry and art, describing ocean dynamics as a kind of planetary choreography. “Fluids are everything,” he wrote in an essay about his work that earned him a DOE CSGF Communicate Your Science & Engineering essay award in 2024. “They are a rush of blood to the head, vibrations in the air around a whisper, the beckoning glow of an alien world.”

That sense of wonder extends beyond the lab. Abdulah is an avid runner and climber who finds parallels between physical endurance and the persistence that research demands. “It’s the same virtues — determination and focus — but the mechanism is different,” he says. “Willing the body to keep moving forward versus willing the mind to keep pushing through code.”

For his next step, Abdulah envisions a postdoctoral fellowship blending planetary fluid dynamics with mission design. The upcoming Europa Clipper mission, which launched in 2024 and will reach Jupiter’s system by 2030, promises to deliver new data for the kinds of models he develops. A similar flagship mission to Enceladus is still under discussion, but he hopes his work will help define its goals and shape analysis of its findings.

“It might take 20 years before we have measurements that test our models,” he says. “That requires patience, but it also means there’s time to build the tools we’ll need.”