Titan is the second-largest moon in our solar system. Titan is bigger than Earth’s moon, and larger than even the planet Mercury. Titan’s atmosphere is primarily nitrogen, plus a small amount of methane. It is the sole other place in the solar system known to have an earth like cycle of liquids raining from clouds, flowing across its surface, filling lakes and seas, and evaporating back into the sky (akin to Earth’s water cycle).
- It has been speculated that life could exist in the liquid methane and ethane that form rivers and lakes on Titan’s surface, just as organisms on Earth live in water.
- Titan is not a pleasant place for life. It is far too cold for liquid water to exist, and all known forms of life need liquid water.