One of Saturn’s moons has features similar to freshwater rivers and salty oceans.

The liquid hydrocarbon seas, lakes, and rivers on Titan have varying compositions, and there is evidence suggesting the presence of active tides or currents.

Our most detailed observations of the lakes on Saturn’s moon Titan have uncovered a diverse landscape, with features resembling both freshwater rivers and salty oceans on Earth. However, unlike Earth’s water, Titan’s lakes are composed of methane and ethane, which remain liquid at the moon’s average surface temperature of about -179°C (-290°F).

Radar data from NASA’s Cassini spacecraft, which orbited Saturn from 2004 to 2017, suggested variations in the properties of these lakes, including differences in composition and surface waves. However, the data was not sufficient to clearly differentiate between the lakes.

Recently, Valerio Poggiali and his team at Cornell University have used an advanced radar technique to map Titan’s seas more precisely. Their findings indicate that the composition of Titan’s lakes changes with latitude, showing a trend where lakes become more ethane-rich as one moves from the north pole towards the equator. “The farther north you go, the lakes are cleaner and more dominated by methane,” says Poggiali.

Earlier radar measurements used signals that were polarized in a single direction, which limited the ability to analyze the variations in the lakes’ properties.