Researchers have replicated the seas of Saturn’s moon Titan, to see if it might be possible to launch a submarine there on a future mission.
The team from Washington State University built a test chamber to hold a mixture of liquid methane and ethane – which make up the bodies of liquid on Titan. The chamber also replicated the freezing conditions on Titan: -300°F (-180°C), and under 60 pounds per square inch of pressure.
"Those aren't the friendliest conditions," said Ian Richardson, who led the study published in the journal Fluid Phase Equilibria, in a statement.
Titan is the only world in our Solar System aside from Earth with bodies of liquid on its surface – albeit in the form of methane and ethane, not water. For that reason NASA has long considered sending an uncrewed robotic submarine of some sort here, and still has plans to do so in the future.
These seas on Titan are extremely viscous, though. They’re probably pretty motionless, with waves no bigger than 1 centimeter (0.4 inches). But under the surface, they might change dramatically in density in different areas, so learning how to navigate them is no mean feat.
Richardson and his team put a cylinder-shaped cartridge heater 5 centimeters (2 inches) long inside their test chamber to simulate the submarine. The heat from the submarine can produce nitrogen bubbles, making it hard for the ship to maneuver and see.
They found that the density increases the deeper you go and the more the temperature drops. One bonus, though, is that the small amount of nitrogen means the lakes will freeze at lower temperatures than expected, so they’re unlikely to form icebergs.
The team plans to continue their research to support NASA’s efforts to develop a Titan submarine. The agency is also investigating the possibility of sending a drone to Titan, separate to this research, to fly through the skies.
"NASA has a lot of brilliant engineers and scientists working on this project and I am confident that they will be able to build a submersible that can handle all of the challenges of Titan," Richardson told IFLScience.
In 2015 a NASA proposal suggested we could send a submarine the size of car to Titan’s seas, which would explore the subsurface region for 90 days. Instruments would sample the ocean and return images, helping us answer whether Titan could be habitable.
Thanks to this latest research, that dream is one step closer to reality.