Saturn’s moon Titan may have the dunes and other features of its landscape sculpted through processes that create hydrocarbon-based substances, forming sand or rock; then seasonal cycles help move grains of this material across the moon’s surface. The conclusion comes from a study led by Mathieu Lapôtre and colleagues, who created a model to explain the cycle processes and the movement of grains.
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- The largest sea on the moon Titan can be more than 300 meters deep
In addition to methane seas and lakes, Titan has nitrogen winds that help carve hydrocarbon sand dunes. This moon is one of the favorite targets for space exploration due to its possible habitability, and it is also the only other known body in the Solar System with a seasonal cycle of liquid transport – exactly the focus of the model developed by the team, which shows how it works. of cycles and can help scientists understand how the moon’s sedimentary environments work together.
But, before creating the model to simulate the formation of Titan’s landscapes, the team had to answer a big question: how can organic compounds, considered much more fragile than inorganic ones, turn into grains capable of forming structures? Perhaps the explanation for this lies on our own planet, as over here, rocks and silicate minerals on the surface turn into grains over time through erosive processes.
When this occurs, these grains move with the help of winds and rivers to be deposited in layers of sediment that will one day form rocks. It could be that something like that happens on Titan, with the difference that the sediments there are made of organic compounds – which had been puzzling scientists, who didn’t know how to demonstrate that these compounds could become grains capable of being transported.
Apparently, the answer behind this lies in ooids, small spherical grains that form through chemical precipitation that allows them to grow, while erosion slows their expansion. These two mechanisms balance each other out, and the researchers believe they are occurring on Titan. “We propose that sintering — which involves neighboring grains fusing into a single piece — could counterbalance the wear and tear when winds carry the grains,” Lapôtre said.
With this hypothesis in hand, Lapôtre and his colleagues worked with data on the climate and direction of grain transport by the wind to explain the formation of dunes on Titan’s equator, mid-latitude plains, and labyrinthine terrain near the poles. In the end, modeling the data showed that winds are common near the equator, supporting the idea that sand grains, critical components of dunes, can be formed there.
The authors predict a break in transport on both sides of the equator, where sintering can create increasingly firm grains until eventually turning them into rocks on Titan’s plains. Grains may also be responsible for the formation of labyrinthine terrain near the moon’s poles. Thus, the authors conclude that, on Titan, there are active sedimentary cycles, which may explain the latitudinal distribution of landscapes caused by seasonal cycles.
The paper with the results of the study was published in the journal Geophysical Research Letters.