By using data obtained by NASA’s Cassini spacecraft, the researchers discovered deep lakes (more than 300 feet, or 100 meters) filled with methane on Saturn’s moon Titan. The team also found “phantom lakes” that fill and empty periodically. It must be noted that Titan is the only known body in our solar system other than Earth with a liquid on its surface. But rather than a water cycle, it has a methane and ethane cycle. The new findings represented further evidence about Titan’s hydrological cycle, with liquid hydrocarbons raining down from clouds, flowing across its surface and evaporating back into the sky. This is comparable to Earth’s water cycle. Titan, with a diameter of 5,150 km, is the solar system’s second largest moon, behind only Jupiter’s Ganymede. It is bigger than the planet Mercury. The research was published in the journal Nature Astronomy.