Saturn’s moon Titan has been the subject of innumerable science fiction works, including Kurt Vonnegut’s classic The Sirens of Titan and Philip K. Dick's The Game-Players of Titan. References to it show up in movies, on TV shows, and on rock albums. Titan might just be the most famous moon in the solar system. But why is Titan so cool? The short answer: because it's more like Earth than you might expect.
Titan has fascinated star-gazers since it was first discovered by Dutch astronomer Christiaan Huygens in 1655. Huygens called the moon Saturni Luna, but it was later renamed by John Herschel for the Titans of Greek mythology.
Despite its relatively early discovery, Titan stumped the scientific community over the next few hundred years. The moon’s hazy atmosphere made it difficult to discern many facts about Titan or unravel its enticing mysteries. More recently, however, thanks to visits by spacecraft like Cassini-Huygens, researchers are learning the exciting truth: Titan has many Earth-like qualities, including flowing liquids, organic compounds and, possibly even a prebiotic environment.
There are plenty of extraordinary things you didn't know about Titan. The fact that it might one day be able to support life is just one of them.
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.