16 Facts About Saturn's Moon Titan, The Closest Thing We Have To A Second Earth

Titan is often described as a primordial Earth, where processes such as flowing liquids and organic compounds point to the potential for life. However, much like Earth's earliest days, Titan isn’t currently hospitable to humans.

The moon's frigid temperatures, low ultraviolet surface exposure, and lack of liquid water and breathable air mean that complex organisms wouldn’t be able to survive there for very long without the aid of technology.

Titan is the only moon in the solar system with a robust atmosphere. Primarily comprised of nitrogen (approximately 95%, compared to Earth’s 78%) and methane (approximately 5%, compared to less than .01% on Earth) with trace amounts of other compounds mixed in, Titan has an even denser atmosphere than Earth. The moon’s atmosphere also extends 10 times higher into space than Earth’s at 370 miles, due to the moon’s lower gravity,

Titan’s hazy, orange aura is thought to be caused by ultraviolet light from the sun splitting nitrogen and methane molecules high up in the atmosphere. A competing theory suggests that rather than a photochemical reaction, Saturn’s strong magnetic field may actually cause the divisions. Regardless of its catalyst, the splitting phenomena creates organic molecules, such as carbon, hydrogen, and oxygen, which are some of the foundational elements necessary for life.

A distinct difference between Titan and Earth is that Titan doesn’t have a significant magnetic field, if any at all. Instead, the moon exists at the edge of Saturn’s massive magnetosphere, where it's sometimes protected from, and sometimes exposed to, the sun's solar winds.

At -290 degrees Fahrenheit (-179 degrees Celsius), Titan is unbearably cold. The moon does get some slight warmth from a greenhouse effect created by atmospheric methane. However, this effect is negated as compounds in the upper atmosphere reflect light back into space, contributing to a less powerful, but nonetheless consequential, anti-greenhouse effect. The lack of ultraviolet penetration also means that Titan’s uppermost atmosphere is much warmer than the moon’s surface, which only receives 0.1% as much light as people do on Earth.

Despite the ever-present cold, Titan does experience seasons. It also has a similar hydrological cycle to Earth, where methane, instead of water, evaporates into the atmosphere and pours down as rain. Winds are also prevalent on Titan, and have been measured at speeds of 270 miles per hour.

Besides Earth, Titan is the only known body in the solar system with stable bodies of liquid on its surface. Titan’s landscape is littered with various lakes and seas, mainly composed of methane and ethane.

Those compounds can exist in liquid form there due to the extreme cold.

Titan’s surface is composed of 50% rocky material and 50% water-ice. Though its average surface height seldom varies more than 150 meters, some taller mountains have been detected. Granular dunes of frozen hydrocarbon cover different areas of the moon, while methane-spewing cryovolcanoes and fluctuating bodes of liquid are thought to constantly reshape the surface.

Liquid water and ammonia, also believed to be emitted from subsurface activities, form “lava flows” along the surface, solidifying into various frozen features and contributing to the moon’s evolving landscape.