Moon and Saturn

Earth has something in common with Titan, the largest moon of Saturn. They’re the only two bodies in the solar system with liquids flowing and ponding on the surface. In the case of Earth, that liquid is water. But on frigid Titan, it’s liquid hydrocarbons – methane and ethane.

Titan is the second-largest moon in the solar system – a bit bigger than the planet Mercury. Its surface is extremely cold – hundreds of degrees below zero. Its atmosphere is thicker than Earth’s, and it’s topped by a dense layer of smog.

The Cassini spacecraft used radar to peer through the clouds. And its findings were remarkable. It discovered rivers flowing across the surface, emptying into lakes and seas. It also found clouds, which occasionally produce rain.

Everything we can see on Titan contains a lot of carbon-based compounds – some of the raw building blocks of life. That’s led to speculation that Titan might have the precursors to life – or even life itself – hidden in a giant ocean below the crust. To be clear, there’s no evidence of life. But future missions to Titan will sniff around for such evidence – perhaps adding to the list of things that Earth and Titan have in common.

Saturn appears quite close to our own moon tonight. It looks like a bright star to the lower left of the Moon as they climb into good view, by about 11 o’clock. But you’ll need a small telescope to pick out Titan.

Script by Damond Benningfield