Titan is Saturn’s biggest moon and a fully 50% bigger and 80% more massive than our own Moon, making it the second-biggest natural satellite in the entire solar system after Ganymede, a moon of Jupiter. With a radius of 2,576 km, Titan is also slightly bigger than Mercury, although it has only about 40% the planet’s mass. Below are some more interesting facts about Titan, the sixth moon to be discovered in the solar system:
– Titan was discovered by Christiaan Huygens.
Titan was discovered on March 25th, 1655 by Christiaan Huygens, with a telescope he had built with the help of his brother, Constantijn Huygens, Jr.
– Titan’s atmosphere is denser than Earth’s
Titan is the only solar system moon that is known to have a substantial atmosphere. In fact, Titan’s atmosphere is denser than that of Mars, and at a pressure of 1.6 bar, it is more than 50% denser than our own atmosphere. In terms of its composition, the primary component is nitrogen, with varying amounts of hydrocarbons such as ethane, hydrogen cyanide, and carbon dioxide. Titan’s atmosphere is also much higher than Earth’s, extending to height of roughly 600 km (370 miles) above the surface compared to 480 km (300 miles) for Earth.
– Titan’s shape changes
Repeated fly-bys of Titan by the Cassini probe has shown that Titans’ surface rises and falls by as much as 10 meters during a single orbit, which is enough to measurably change the moon’s shape as it orbits Saturn. These findings suggest that Titan’s relatively thin crust overlays a deep sub-surface ocean of liquid that may or may not be water, and that may or may not also decouple the crust from the core, which would allow for the high degree of observed deformation of the moon.
– Titan has hydrocarbon lakes
Titan is the only body in the solar system other than Earth that is known to have liquid on its surface. The image below shows an extended system of lakes and drainage channels that stores liquid hydrocarbons (liquid methane and ethane) that precipitates from Titan’s atmosphere. While this is roughly analogous to the hydrological cycle on Earth, it is not certain how long the episodes of precipitation lasts, although it is suspected that each episode delivers several tons of precipitation each time it occurs. The white areas on this image are unmapped regions.
– Titan may have ice volcanoes
Although no ice volcanoes have been positively identified, it is thought that ice volcanoes are the only mechanism by which the high levels of methane in Titan’s atmosphere can be explained since there is not enough liquid methane on the surface to maintain the observed levels of atmospheric methane. While two possible ice volcanoes that seem to be spewing water and ammonia (the source of atmospheric methane) were identified in 2008, the discovery is not yet confirmed as being ice volcanoes.
– Titan does not have high mountains
While several mountains have been identified on Titan, none are very high, which at first glance, is strange given the fact that the moon is tectonically active. One possible explanation for the lack of high mountains is that Titan’s crust is very soft, which would prevent the formation of high fold mountains like the Himalayas on Earth. Nonetheless, the highest mountain on Titan is located in the Mithrim Montes range, and measures all of 3,337 meters tall.
– Mountains on Titan are named after mountains in Middle-Earth
All the mountains and collections of hills on Titan are named after mountains, or mountain peaks in Middle-earth, a fictional world created by J.R.R. Tolkien (1892-1973) and whose story is told in the Lord of the Rings trilogy and other works. Some examples include Angmar Mons, named after the Mountains of Angmar, Erebor Mons, named after Erebor [The Lonely Mountain], and Moria Mons, which is named after the Mountains of Moria.
– Life could arise on Titan
Experiments have shown that with the addition of UV radiation, polymers such as tholins and other complex organic molecules can be created from Titan’s atmosphere. In fact, the building blocks of DNA and RNA as well as several proteins and amino acids have been produced when energy was applied to a cocktail of gases similar to those in Titan’s atmosphere, However, the obstacles to life arising on Titan remain formidable, and any analogies to life as we know it are inexact. Chemical and environmental conditions in the moon’s cold hydrocarbon lakes are so different from conditions on Earth that even if life did arise on Titan, there is a possibility that we may never recognize it as such.
– Titan’s “sand” dunes consist of organic soot
While some features, such as extensive dune fields on Titan strongly resemble dune fields on Earth, the material of which the dunes are made is not silicate sand. Some investigators hold that the dunes consist of rock that was eroded by liquid methane, while others are of the opinion that the dunes consist of organic compounds that have rained down from the moon’s atmosphere, much like terrestrial snow. What is certain about the dunes is that they contain less water than the rest of Titan, which supports the theory that photochemical reactions in Titan’s atmosphere continuously form a sort of organic “snow” that rains down to produce the dunes.
– Titan’s has few impact craters
Few impact craters have been positively identified on Titan, which suggests that the surface has undergone, or is undergoing a continuous process of recycling. In fact, studies have shown that Titan’s surface is only about 100 million to 1 billion years old, although the moon itself is as old as the rest of the solar system. While the geological processes that appear to be obliterating the large impact craters on Titan are not yet understood, it is thought that the dense atmosphere of the moon has somehow been protecting the surface from small and intermediate-sized impactors.