It has been over ten years since the spacecraft Cassini has transmitted the first clear images of Titan, the largest moon of the planet Saturn. Astronomers have spent years to analyze all the data provided by the camera, and finally, introduced the world’s first topological map of the surface of the satellite. It turned out that Titan has much more in common with Earth than one would assume.
Like Earth, Titan has seas of liquid. However, unlike water, seas on Saturn are composed of superfluid hydrocarbon compounds. Perhaps another noteworthy difference is that the surface of these seas are very calm, you might say, clean as a whistle. However, not only seas a satellite similar to our planet.
Astronomers from Cornell University used the last obtained topographic data of Titan and found that the three largest sea of the satellite have the same equipotential surface of sea level as our oceans. This fact in itself is of great interest to scientists, but more striking is that the researchers were able to determine even such details.
“We measured the level surface of the liquid at the other the outer body, located 10 astronomical units from the Sun, with an accuracy of about 40 centimeters,” explains astronomer of Cornell University’s Alex Hayes.
“We measured the geoid Titanium. This is a form that the surface of the satellite takes under the influence of gravity and rotation. The same form, i.e. shape of the geoid, has our Land.”
Interestingly, the data also contain information hinting at some features of the distribution and movement of liquids on the satellite, mostly presented in the form of condensed molecules of methane and ethane. Scientists suggest that the sea of the satellite have the same level because they can connect some channels, either on the surface or under it. The channels are large enough, and therefore allow even distribution of the liquid on the surface. According to Hayes, the second option (with sub-surface channels) is more likely.
“We don’t see any empty lakes whose level would be below the level of the local lakes. Even if this level is reduced, then through time again it is increasing. This may indicate that beneath the surface of lakes are the channels through which the liquid can be distributed between the pools,” says Hayes.
In addition, it can also speak about the fact that stocks of liquid hydrocarbons on Titan could be much more than visible at first glance.
The topological map could help astronomers better understand how the fluid is distributed via satellite, but at the same time opens a new mystery to solve. Some liquid-filled crater on the surface very similar to the geological structure, well-known on Earth and are called karsts. They are associated with the activity of water is expressed in dissolution of rocks and the formation of these voids, as well as certain forms of relief.
As on Earth, the karst structure of Titanium do not have obvious channels through which between them could flow fluid. But, in contrast to our clusters, karst Titanium have sharp raised edges. Scientists suspect that these holes are expanding. Amazing looks and the largest lake of Titan, located in the South. It is a fluid-filled karsts combined together.
“Many things are still unclear. For example, the decision of a question with karsts can be the key to understanding the evolution of polar basins of Titan,” says Hayes.
Maybe Cassini longer with us and no – recall probe deliberately dropped on Saturn, but his legacy and discovery will continue to indulge our curiosity about Saturn and its satellites for many years.