Earth is not the only place in the solar system with rivers, lakes, and seas. Titan, Saturn's largest moon, also has these features, but they are made of liquid hydrocarbons like ethane and methane instead of water. Titan possesses hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth, New Scientist reported.
A new paper published in Nature Communications provides more insights into Titan's unusual bodies of water, including waves, currents, estuaries, and straits. This research utilises archived data from NASA's Cassini mission, which orbited Saturn from 2004 to 2017, and whose Huygens probe sent back the first images of Titan's surface in 2005, revealing ancient dry shorelines and methane rivers.
As NASA prepares to launch its Dragonfly spacecraft to Titan in 2027, gaining more information about Titan's bodies of water will aid mission planning.
Titan is the most Earth-like place we know, with an atmosphere (98% nitrogen and 2% methane), rain, ice, lakes, oceans, valleys, mountain ridges, mesas, and dunes. Its landscape is dominated by large dune fields, flat plains, and polar regions with extensive seas and lakes of liquid hydrocarbons. Titan's surface temperature is around -290 degrees Fahrenheit (-179 degrees Celsius), and its gravity is 14% of Earth's. It receives just 1% of the sunlight Earth does.
Though Titan is vastly different from Earth, aerial and radar images show how the flow of liquid methane has shaped its surface in a manner reminiscent of Earth.
Titan's small lakes are over 300 feet deep and 10 miles wide, perched atop hills and plateaus. New research using Cassini's radar data on three of its polar seas—Kraken, Ligeia, and Punga Mare—reveals even more about these alien waters. The lakes contain varying levels of methane and ethane, with more methane in rivers than in seas, and larger waves near coasts, estuaries, and straits, suggesting tidal currents.
Previous research has shown that Titan's rivers don't carry enough flow or sediment to form deltas but can behave like wide, fast-flowing rivers on Earth, such as the Mississippi.
Scheduled to reach Titan in 2034, NASA's Dragonfly mission will last for two years. The mission will include a rotorcraft that will fly to new locations every Titan day (16 Earth days) to collect samples of the moon's prebiotic chemistry. It will also search for chemical biosignatures, investigate the moon's active methane cycle, and explore prebiotic chemistry in both the atmosphere and on the surface.
“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”
