The shattering impacts had torn huge craters in the Martian crust, blasting tons of dust and steam into Mars’s threadbare sheet of air. As the temperature rose, buried oceans of Martian permafrost roared forth, leaving networks of twisted badlands and vast expanses of damp mud, smooth and sterile as a television. On these great playas and on the frost-caked walls of channels, cliffs, and calderas, transplanted lichen had clung and leapt into devouring life. In the plains of Eridania, in the twisted megacanyons of the Coprates Basin, in the damp and icy regions of the dwindling poles, vast clawing thickets of its sinister growth lay upon the land—massive disaster areas for the inorganic.