5 amazing facts about Saturn's largest moon Titan that you probably didn't know

There are over 200 known moons in the solar system. Yet, Titan, Saturn's largest moon, holds a unique place among them as the only moon in the solar neighborhood with a substantial atmosphere.

Like Earth, Titan's ‘golden hazy atmosphere’ is composed mostly of nitrogen, with a small amount of methane. However, at the surface, the atmospheric pressure of the moon is about 60 percent greater than Earth's, according to NASA. The atmosphere on Titan also extends to an altitude 10 times higher than Earth's and reaches nearly 370 miles into space. This is because its gravity is weaker and doesn't hold on to the atmosphere as tightly as our planet does.

This image is an artist's illustration of the Huygens probe descending through Titan's atmosphere.

About 5% of Titan's atmosphere is methane, whose molecules, along with those of nitrogen, break down and recombine to form a variety of organic chemicals. However, scientists are still not sure about the source from which Titan keeps getting all this methane. Since sunlight constantly breaks down the methane in the atmosphere, it should be depleted by now. But Titan still has plenty of methane in its atmosphere, which hints that there is a source that keeps on replenishing it. 

Scientists speculate that it might come from the icy volcanoes, which release chilled water and ice instead of hot lava. Scientists have not been able to say for sure if some other process is responsible for this.

Observations made by NASA's Cassini spacecraft revealed that Titan has an underground ocean of liquid water. The European Space Agency’s Huygens probe also hinted at the same, as radio signals indicated the presence of an ocean 35 to 50 miles below the surface. This discovery of a global ocean made Titan one of the few candidates in the solar system with the potential to support life.

A more recent reanalysis of the Cassini mission data, however, suggests that the moon may not have a global liquid ocean after all. Its interior could be composed of ice instead, along with slush layers and small pockets of warm water near its rocky core.

But the absence of a global ocean doesn't mean that Titan does not have the potential to support basic life forms. The pockets of water could be as warm as 20 degrees and could be cycling nutrients from the rocky core to a solid icy shell on the surface.

The picture is an artist's concept of NASA's Cassini spacecraft during one of its flybys of Titan.

Titan's surface is more Earth-like than most other worlds in the solar system, even though it's extremely cold (-179 degrees Celsius). Flowing methane and ethane carve river channels on Titan's surface and fill lakes with liquid gas, making it the only solar system world besides Earth with so much liquid activity on the surface.

Titan also has dark dunes across its surface in its equatorial regions. These dunes are composed of dark hydrocarbons, which have the appearance of coffee powder.

The image taken by the ESA's Huygens probe is that of a soft, sandy riverbed on Titan's surface.

Titan orbits Saturn at a distance of about 759,000 miles, while the orbit of the ringed planet itself is approximately 886 million miles away from the Sun. Thus, Titan is about 9.5 times farther from the Sun than Earth. Because of this distance, sunlight takes about 80 minutes to reach Titan and is around 100 times dimmer than what we receive on Earth.

Each season on Saturn lasts more than 7 years. And since Titan orbits roughly along Saturn's equatorial plane and its tilt relative to the Sun is the same as the ringed planet's, its seasons are also as long as those on Saturn.