There is always some water in ice.
NASA has a mantra of “follow the water,” based on the general idea that where there is water, there is life, and that cells require water to grow and metabolize. But it’s important to remember, Christner says, that even in ice there is nearly always a small amount of liquid water. As I sit in his office, he pulls up a microscope image of ice crystals on his computer monitor. The ice crystal structure looks like an opaque jigsaw puzzle made up of large hexagonal pieces. But Christner points out clear, narrow gaps between the edges and points of the ice puzzle-pieces.
(And microbes are probably sneaky.)