Glaciers harbor microbes. In small, ice-covered lakes created by glacial runoff live fibrous mats of algae and plankton. And in a paper in last week's Science, researchers decribe an aggregate community of microbes living in oases of liquid water inside the lake ice. These ecosystems raise the hopes of exobiologists, people who look for life on other worlds. If life can make it there, maybe life can make it anywhere-Mars, or the ice covered seas of Jupiter's moon Europa-as long as there's liquid water.