The mystery of Titan unveiled: why Saturn's moon retained its atmosphere when it was expected to lose it.

The only world in the Solar System, aside from Earth, that has a thick and dense atmosphere is Titan. This is Saturn's largest moon and the second-largest moon in the Solar System. Titan's atmosphere is composed of 95% nitrogen and 5% methane. The presence of methane in Titan's atmosphere puzzles scientists. It should have disappeared within a few tens of millions of years, leading to the freezing and vanishing of Titan's atmosphere. However, that has not happened. This indicates that there is a process maintaining Titan's atmosphere in a stable state. The authors of a study published in the journal Geochimica et Cosmochimica Acta have uncovered the secret, as reported by Universe Today.

Titan is second in size only to Jupiter's moon Ganymede. The surface of Saturn's largest moon is covered with sandy dunes, icy mountains, and liquid hydrocarbon lakes made up of methane and ethane. Scientists believe that beneath Titan's crust lies a vast ocean of liquid water, increasing the likelihood of microbial life existing there.

According to the researchers, although Titan is only 40% the size of Earth, its atmosphere is 1.5 times denser than that of our planet. Therefore, even with lower gravity than on Earth, walking on Titan's surface would feel like swimming underwater. Despite the presence of an atmosphere, humans cannot live on Titan, as there is nothing to breathe.

Scientists state that the presence of methane is crucial for the existence of Titan's atmosphere. Methane is continually removed from the atmosphere due to sunlight and should have disappeared over the course of several tens of millions of years, which would have led to the loss of Titan's atmosphere.

To determine how Titan's atmosphere continues to exist, scientists conducted experiments and obtained interesting results.

Six years ago, researchers proposed that methane in Titan's atmosphere might be continuously replenished by heating large volumes of organic material in the moon's interior. This process releases nitrogen and methane, which seep to the surface and enter the atmosphere. This theory was developed based on data collected by the Cassini spacecraft, which studied Saturn and its moons from 2004 to 2017.

Scientists conducted experiments in which they heated organic materials to temperatures ranging from 250 to 500 degrees Celsius under pressures up to 10 kilobars. This simulated the conditions found beneath Titan's surface. As a result, the scientists observed the formation of sufficient methane to replenish Titan's atmosphere to the level currently observed. This confirms the theory.