The Weather On Titan: Windy With A Chance Of Methane Mist

In 2005, the European Space Agency’s Huygens probe landed on Saturn’s largest moon, Titan, and sent back images of a landscape shaped by forces similar to those on Earth. However, unlike Earth where water shapes the surface, on Titan, where the temperature is -179 degrees Centigrade, it is methane that shapes the surface. Methane exists as a gas in the atmosphere, as a liquid in rivers and oceans, and as a solid in ices on Titan due to conditions being balanced around methane’s triple point.

The existence of methane in these three states suggests that Titan experiences complex weather patterns similar to Earth. However, until recently, no one had simulated how Titan’s lakes and seas influence its weather. Audrey Chatain at the Southwest Research Institute in Boulder, Colorado, and her team have now simulated the 3D weather patterns around Titan’s lakes for the first time. Their work shows that 2D wind models overestimate some properties of lake breeze and underestimate others.

Chatain’s team also modelled specific lakes on Titan and found that larger lakes generate stronger winds, and their individual weather patterns can merge to form a local microclimate with its own complex weather patterns. These winds influence evaporation into the atmosphere, and the team estimates that the lake evaporates at a rate of 6cm per Earth year. The simulations also suggest that some sections of lakes might accumulate enough methane vapor to form a thin fog.

The weather on Titan has significant similarities to the weather on Earth, despite its atmosphere being denser and wind speeds being lower due to less energy in the atmosphere at that distance from the Sun. However, there are still many questions about Titan, such as where all the methane comes from and how Titan’s temperature is carefully balanced at methane’s triple point. Further exploration of Titan could provide answers to these questions.