Multiple Layers Found in Titan's Atmosphere

Astronomers were recently able to determine in a new investigation that the atmosphere surrounding the Saturnine moon Titan has multiple layers, just like our planet's. This is a remarkable discovery, since it represents the first time a layered atmosphere is discovered around another celestial body.

With this in mind, Titan becomes even more similar to Earth, even though it may not appear so at first. There are huge temperature differences between the two objects, as well as important differences when it comes to the chemical composition of the atmosphere surrounding both worlds.

Yet, in a strange way, the Saturnine moon also has lakes, rain, lightning, clouds and other, similar manifestations of an active atmosphere. The most important thing that separates it from our own is the fact that it's powered by hydrocarbons such as methane and ethane, and not water.

In addition, Titan's atmosphere is also thicker and a lot denser than Earth's. Visible-light cameras or telescope cannot pierce through it, so the only way to observe the moon's surface is via radar. Such studies were conducted using the NASA Cassini spacecraft.

Over the years, numerous scientists have engaged in debates about the nature of this alien atmosphere, with some suggesting that it may indeed have multiple layers. Others argued that that was not the case.

However, the latest study demonstrated the latter to be wrong. A boundary layer was identified at the bottom of the atmosphere, where it interacts with the surface. This layer contains most clouds and generates winds, while at the same time helping sculpt the surface of dunes and other landscape features.

“This layer is very important for the climate and weather — we live in the terrestrial boundary layer,” explains the leader of the new investigation, National Center of Scientific Research (France) expert Benjamin Charnay.

In the new, 3D model of Titan's climate the team developed, it became apparent that the moon's boundary layer is actually divided in two sectors. The former stretches about 800 meters (2,600 feet) up in the air, and displays the same properties over time.

The uppermost portion of the boundary layer is about 2 kilometers (1.2 miles) thick, and its properties change with the seasons. “The most important implication of these findings is that Titan appears closer to an Earth-like world than once believed,” Space quotes Charnay as saying.

“3D models will be very useful in the future to explain the data we will get about the atmospheres of exoplanets,” he adds. Details of the new study appear in the January 15 issue of the top journal Nature Geoscience.