The Negev desert that sprawls across Israel is one of the driest places on Earth, but deep below its surface is a different story. Held in the sandstone deep underground is a reservoir of fossil water that lay undisturbed for hundreds of thousands of years. Researchers know this water is old, because it can’t have been replenished by any recent rainfall. There’s barely enough every year to moisten the ground - just a few inches at most. Read more.