Titan, Saturn’s largest moon, is a valuable analog to Earth for studying alien hydrology. Its surface features clouds, rain, rivers, lakes, and seas, but unlike Earth, its liquid is made of methane and ethane that can remain liquid under Titan’s frigid atmospheric conditions.
Scientists applied the same logic used on Earth to Titan’s unique environment. However, they discovered something unexpected – almost all large river deltas are missing from Titan’s coastlines. This caught the attention of Sam Birch, an assistant professor at Brown University, who wondered if these features were hidden or absent altogether.
To investigate further, Birch and his team created a model that simulated what Earth’s coastlines would look like through Titan’s radar conditions. They found that even with altered properties, major coastal features remained visible in the synthetic SAR images, suggesting that Cassini should have seen Titan’s deltas.
Despite this, the researchers still found that only about 1.3% of Titan’s coastal rivers ended in deltas. This is significantly lower than on Earth, where nearly every major river forms a delta at its mouth.
The team proposed several hypotheses for the absence of deltas, including sea-level cycling, strong coastal winds, and sub-aqueous flows. However, more data is needed to understand these interactions fully.
This study highlights the value of improving future instruments to reveal Titan’s river networks and coasts in greater detail. Such advancements could not only refine research on Titan but also provide insights into Earth’s own changing coasts in the face of sea-level rise and erosion.
Source: https://www.earth.com/news/why-does-saturns-moon-titan-have-rivers-but-not-deltas-scientists-have-an-idea