Titan is the largest moon of Saturn and NASA hopes to send a submarine to this alien world to explore the mighty oceans of methane and ethane on its alien surface. Such a probe would need to have the ability to traverse vast distances in the liquid seas, avoid obstacles, and withstand temperatures as low as -185C (-300F).
Washington State University (WSU) researchers are testing how such a submarine might be designed to explore these frozen seas of hydrocarbons. To do this, Ian Richardson of WSU and his team developed a model of the seas, into which they placed a heated body, two inches long, representing the autonomous craft.
“One of the biggest challenges for researchers was understanding bubbles in the Titan seas. Add a submarine powered by a heat-producing machine into the very cold Titan liquid, and nitrogen bubbles will form. Too many bubbles would make it hard to maneuver the ship, see, take data and manage ballast systems,” Washington State University researchers reported in a press release announcing their study.
Another challenge facing NASA in their quest to explore the seas of Titan with a submarine is that the relative concentrations of the two compounds differs in various locations around the satellite, altering the density of the seas, and with it, the buoyancy of the craft.
“Titan is the only known celestial body in our solar system other than Earth with stable liquid seas on its surface. The thermodynamic properties of Titan’s seas have not been well characterized,” Richardson and his team reported in the journal Fluid Phase Equilibria.
Building a camera capable of taking video images under these harsh conditions is yet another hurdle on the way to designing the submersible, which NASA hopes to launch sometime in the next 20 years.
Titan is the second-largest moon in the solar system, behind only Ganymede, which orbits Jupiter. This massive natural satellite holds some unique properties not seen elsewhere in the solar system, including its extensive network of hydrocarbon oceans. Like Venus, the atmosphere of Titan covers the world in continuous cloud cover. This world is also home to rain, although, unlike Earth, the precipitation there comes in the form of methane.
Due to the presence of small quantities of nitrogen in the chilly seas, it is unlikely that icebergs form in the oceans of Titan, researchers report.
NASA is currently considering sending this submarine to the northern sea of Titan, Kraken Mare, roughly equivalent in size to the Great Lakes. Once there, the Titan Sub will explore currents, the ocean floor, and the chemical makeup of these alien seas. The vehicle would then surface, sending its findings back to Earth for analysis.
Methane on Earth is often seen rising from swamps, and Benjamin Franklin described it as “flammable air.” Ethane was first produced by pioneering chemist Michael Faraday in 1834 from potassium acetate, a salt commonly used today to deice runways at airports.