The absence of visible traces of tectonics on the surface of Titan does not allow us to consider this moon of Saturn the closest analogue of the Earth, and brings it closer to Mars, where geological processes have died out in the distant past, planetologists say in an article published in the journal Science.
“It's amazing that there are three worlds in the solar system at once, where rivers were the main sculptors of the landscape, either in the past or even today. We had a unique opportunity to learn from these rivers how the histories of these worlds differed,”said Taylor Perron of the Massachusetts Institute of Technology (USA).
Titan, as scientists explain, is very similar to Earth in many ways - it rains on it, soil erosion is present, and certain geological processes take place in its depths, caused by tidal forces and gravitational interaction with Saturn. Titan has seasons, and its weather processes are almost as complex as their counterparts on Earth.
The differences lie in the "stuffing" of the interior and atmosphere of Titan - its rain drops are composed of methane, the surface is covered with ice and snow from hydrocarbons, and the role of the hot mantle is played not by molten rocks, but by the supposed warm ocean that exists in the bowels of this Saturnian moon.
Perron and his colleagues claim that in fact, Titan is an analogue of young Mars, not Earth, having studied the structure of its river beds, feeding large lakes and "seas" at the north pole of Saturn's moon.
River channels on Earth and the nature of their flow over the planet's surface often change not only due to abrupt climate changes, landslides and other "rapid" changes in the landscape, but also under the influence of slow geological processes - as a result of the formation of mountains, the movement of tectonic plates and rises or lowering the height of the plains and other low-lying areas.
As a result, rivers often flow in the “wrong” direction, moving not along the steepest slope from top to bottom, but randomly, and sometimes even from bottom to top, “gnawing” their way through mountains and steep slopes. Such traces of tectonic activity are not found on Mars, which means that the surface of the red planet has remained practically unchanged throughout the time when rivers existed on it.
Guided by this idea, planetary scientists tried to find out whether Titan was closer in this respect to Earth or to Mars by analyzing photographs of its rivers taken by the Cassini probe during its approach to the moon of Saturn.
Promotional video:
It turned out that Titan was more like Mars - all rivers on its surface flow from top to bottom along the most optimal path, which indicates the absence of tectonic processes in the bowels of Titan. This does not negate the fact that its bowels may be geologically active, but suggests that there are no tectonic plates and moving "continents" on Titan, similar to those on Earth.
“The Cassini mission ends in September this year, and we will never see new photographs of Titan taken by its cameras. Therefore, any opportunity to supplement our understanding of the appearance of this planet, in addition to observations with telescopes and the study of old images of "Cassini", will help us prepare to send new probes to Titan, "concludes Perron.
