Where once the sea had been but one great big expanse of water, suddenly four rivers formed, and these four meandered from beneath the mountains and spread across the whole country.

We have very strong evidence that a vast sub-surface ocean exists on Jupiter's moon Europa. It's an incredibly compelling place to explore in our search for life beyond Earth.

The fog lay stretched in an unbroken sea over the plain, but at the village of Schlapanitz on the high ground where Napoleon was, surrounded by his marshals, it was now perfectly clear.