Unlike many other bodies in the solar system, Saturn, the giant satellite of Saturn, resembles Earth in many ways.
Moreover, Titan is the only moon in the solar system that has a dense atmosphere and produces many quasi-Earth-like weather phenomena, such as methane rain, which feeds rivers and lakes.
Although much of Titan’s landscape does not resemble Earth at all, other aspects of this icy moon are not so different, such as the azure sand dunes, the existence of which has been somewhat mysterious.
On Earth, sand dune-forming sediments are composed of inorganic silicates, but the chemical composition of titanium is more different.
“Sediments on this moon of Saturn are thought to consist largely of mechanically weak organic grains and are prone to rapid dust abrasion,” wrote a team of researchers led by Stanford University planetary geologist Matthew La potre.
Rapid abrasion means that in a sufficient amount of time, the grains of sand in the titanium dunes will become more and more clear until they eventually turn to dust.
Gradually, this light dust will become so finite that it will rise into the atmosphere and make it impossible for it to form cohesive structures resembling giant dunes, requiring larger, coarser particles.
“When the wind moves the grains, they collide with each other and with the surface, and over time, these collisions reduce the size of the grains,” Lapotre explains.
However, because there are huge sand dunes on Titan, researchers suggest that there is some unknown mechanism of their growth on this moon that could strengthen the grains and counteract the abrasive forces.
Whatever that power is, it must have been there a long time ago.
“The equatorial dunes of Titan have probably been active for tens and hundreds of thousands of years. “The preservation of titanium dunes over geological times requires a mechanism that produces sand-sized particles at equatorial latitudes,” the researchers wrote.
In a new study, scientists have speculated as to what this mysterious mechanism might be, and their inspiration came from oids – small, rounded, sedimentary grains found on the Earth’s seabed.
Unlike many other forms of sand, ooids are accretion formations that are formed from smaller particles, in a marine environment, through chemical sedimentation.
According to the researchers’ modeling, a similar mechanism could explain the presence of organic sediments on titanium, which allow the particles to clump together, counteract the constant abrasion force, and maintain the particle size equilibrium.
“It easily allows active dust dunes to form at the equator, with a certain amount of dust, but only a small amount of dust will turn into grains of sand over time,” the researchers said, noting that their calculations also take into account the presence of other sandstone formations. At the poles.
Researchers say that on Titan, like Earth and possibly Mars, there is an active cycle of sedimentation that can explain the longitudinal redistribution of the landscape through episodic abrasions and seasonal coagulation.
Although a group of researchers realize that their explanation for the active cycle of Titan sediments is still a hypothesis and other scenarios can not be ruled out, they are still convinced that it completely coincides with what we see on this strangely familiar moon, once called “Earth”. On the crazy version. ”
“We were able to solve the paradox of why there could be sand dunes on Titan for so long, even if the materials there are very weak. “It’s shocking to think that there is an alternative planet so far away, where everything is so different, but still so familiar,” said study author Matthew La potre, a planetary geologist at Stanford University.
The study was published in Geophysical Research Letters.
Prepared according to news.stanford.edu and ScienceAlert.