“With its thick atmosphere and organic-rich chemistry, Titan resembles a frozen version of Earth several billion years ago, before life began pumping oxygen into our atmosphere.

Because Titan is smaller than Earth, its gravity doesn’t hold onto its gaseous envelope as tightly, so the atmosphere extends 370 miles into space.

As on Earth, the climate is driven mostly by changes in the amount of sunlight that come with the seasons, although the seasons on Titan are about seven Earth years long.

Titan’s ‘water’ is liquid methane, CH4, better known on Earth as natural gas. Regular Earth-water, H2O, would be frozen solid on Titan where the surface temperature is -180°C.

With Titan’s low gravity and dense atmosphere, methane raindrops could grow twice as large as Earth’s raindrops. As well as this, they would fall more slowly, drifting down like snowflakes.

Scientists think it rains perhaps only every few decades”.