Life clings on in the driest corners of the Earth

Down desolation road IT DOES not rain much in the Atacama desert. A 1,000km strip of land running along the Chilean coast, it is Earth's driest desert outside its poles. Average annual rainfall in certain parts can be as low as a millimetre or two a year, and some Atacaman weather stations have never seen a drop of water. Yet it does rain occasionally. And as Dirk Schulze-Makuch, an astrobiologist at the Technical University of Berlin, and his colleagues report in Proceedings of the National Aca...