There are plans afoot to sail a ship upon a methane sea on Titan, one of Saturn's moons.
I could just stop there; rarely have I typed a more glorious sentence than that. I am rarely switched onto astronomy, as it seems to involve far too much standing around in a freezing cold garden squinting through the eyepiece of a telescope at something that may or may not be Mars, and not nearly enough visiting the Hadron Collider hand-in-hand with Brian Cox. But think of it: if this project gets funding (and there's every chance), and if it comes off, in a few years time there could be a craft made by human hands sailing purposefully on an alien ocean. Titan is a place of extreme temperatures (minus 290F), sufficient to ensure that methane exists as a liquid rather than the gas it is on our planet. There is no hope of finding life in such conditions; but perhaps the clues to what sort of conditions existed before life began.
Saturn is perhaps the most romantic of planets. Not the biggest, not the closest, not the most colourful, yet certainly the most recognisable with its rings of ice, debris and dust. These rings spin to keep pace with the planet, and cradle within them over sixty moons, the largest of which is Titan. Titan is unique within the known universe in that it is the only moon known to possess an atmosphere. It has weather. Alien wind and alien rain. And weather produces features that we would recognise - lakes and rivers and valleys and beaches. It's not likely to become a top holiday destination, owing largely to a bit too much nitrogen in the air as well as the freezing cold and the distance. But if we could, if we could sail in that ship: ah... we would see something that looked a little bit like home, even as the ice and dust of the millennia whipped across the skies.