51 - Kraken Mare

Nine years ago the Wells-Dyson satellite picked up images of what appears to be some sort of wreckage on the floor of Titan's biggest hydrocarbon ocean - Kraken Mare.

The discovery prompted eccentric billionaire Jennifer Barrie to fast-track an expedition to the mysterious moon of Saturn.

The three British astronauts who have just arrived in Titan's orbit have only one job - find out what's lying under Kraken Mare.

And potentially answer one of humanity's biggest questions.

Are we alone in the universe?