Scientists have compiled Titan's first global geological map, one of Saturn's main moons, thanks to data provided by the Hyugens spacecraft – launched in 1997 with the Cassini mission. As well as being the only moon in the solar system with clouds and a dense atmosphere of nitrogen and methane, evidence shows that Titan is covered with organic material.
According to research published in the journal Nature Astronomy, Cassini's infrared and radar instrument data have succeeded in removing the dense layer of the atmosphere, which obscures a larger view of the moon. With this information, scientists reconstructed and mapped Titan's surface, presenting six major geological forms, age, distribution, and details about the poles.
Titan has liquid objects on its surface, similar to those on Earth, but rivers, lakes, and seas are made of liquid ethane and methane. These compounds form clouds and rain gas from the sky. This methane cycle is the driving force behind Titan's geology – at the poles, water vapor helps methane stay in its liquid state. Around the equator, drier climate keeps the wind-carved hills intact.
In other words, we found different geological formations according to latitude. But there is one more prominent feature around the moon: the existence of organic plains.
Rosaly Lopes, research writer and senior researcher at NASA's Jet Propulsion Laboratory, explains that "the strong latitudinal dependence of different units provides clues about how the methane cycle operates," although he acknowledges that the mystery still exists. "For example, most of the surface is covered with organic material, especially plains (65%) and sand dunes (17%). These are formed, we think, organic material that falls from the atmosphere and is driven by the wind. So this tells us that the wind is very important in forming the surface of Titan. "
This discovery that much of Titan is covered with organic plains is a surprise to researchers. Because, according to Lopes, "people tend to know and study Titan resources that are the most 'interesting', like lakes (which only cover 1.5% of the surface)."
Valuable information for the Dragonfly mission
In 2026, NASA will send a Dragonfly mission to explore Titan starting in 2034. The main purpose of the spacecraft is to visit the impact crater, where critical life materials are believed to have mingled when some space objects hit the ground in the past. maybe tens of thousands of years ago.
This new moon map can help provide context for anything Dragonfly can find, according to Lopes. "We still have many questions about Titan. For me, the most interesting thing is related to habitability, "said the scientist, who expects many answers about the composition and potential habitability when Dragonfly shows data directly from Titan's surface. For him, "the fact that we have so much organic material on Titan has important implications for life."
Lopes and his team are working on Titan's evolutionary landscape model to understand how organic matter moves across the surface and where and how it can penetrate ice sheets. "Organic products that reach the ocean, the most livable environment, are fundamental to habitability," concluded the researcher.