Microbes live wherever water is found at the Earth's surface, and the water found at the beds of ice sheets and glaciers is no different. Microbes grow beneath ice sheets, and help to convert the rock and sediment that glaciers crush up into fertiliser (N, P and Fe) that helps the microscopic plants in surrounding streams, lakes, coastal waters and oceans to grow. The microbes also produce greenhouse gases, such as carbon dioxide and methane. Just where the microbes which live beneath the ice sheets, for example in the subglacial lakes beneath Antarctica, get their energy to grow is a problem, since there is no light in these cold, dark habitats. The microbial communities beneath ice sheets are destined to die out unless something is continually supplying them with an energy source other than light. We think that "something" is something to do with glaciers crushing the rocks at their beds. The minerals are held together by tiny positive and negative electrical charges. These charges cancel each other out usually, but when the mineral is split by the huge weight of the glacier, their surfaces contain tiny positive and negative electrical charges, called radicals. These tiny charges are very reactive, so reactive that the positive charges grab OH from water and leave behind hydrogen gas, and the negative charges grab H from water and leave behind hydrogen peroxide. particular types of microbes enjoy feeding on hydrogen, since it produces lots of energy. The hydrogen peroxide is not immediately friendly to microbes, but it does react very well with organic matter in the crushed rock, producing carbon dioxide and other small organic molecules that microbes can use for energy sources. Some microbes combine hydrogen gas with carbon dioxide to make methane, and other microbes can use the methane as an energy source. So, the crushing and wetting of rock by glaciers and ice sheets produces a set of chemicals that can be used as energy sources by lots of different bacteria. Glaciers and ice sheets crush their bedrock continuously, and so we believe that this gives a continuous source of energy and chemicals to microbes living at their beds. We need to test these ideas by crushing simple rocks, such as quartz, and organic matter, such as peat, in the laboratory and measuring what types of chemicals come off the crushed material when we add water to it. If we're right, this will be a big step in understanding how life persists under glaciers and ice sheets. This is important, because in the past, when the earth was completely frozen on Snowball Earth, life was likely to have persisted under the ice sheets that covered large parts of the land surface. We hope that a Nuclear Winter never arises, but if it did, life in the form of microbes would persist beneath the ice sheets. Ice sheets occur on planets in the Universe apart from Earth, and it just might be crushing provides the chemicals to sustain life beneath them. CRUSH2LIFE will test whether we are right in thinking that these examples have any substance.