Two seprate groups of researchers in US are proposing to look for neutrinos(the most abundant particles in the universe) under the earth's crust. The earth is liberally salted with radioactive elements. When these decay, they produce vast amounts of heat. This radiogenic heat helps to keep the mantle -the molten rock which constitutes most of the planet-molten. It also drives convective flows within the mantle, and these flows shape the continents and keep them drifting over the earth's surface.