Where and how much are they? Are they present in the core of the Earth? Detection of antineutrinos generated in the Earth provides: 1) information on the sources of the terrestrial heat, 2) direct test of the Bulk Silicate Earth (BSE) model and 3) testing of non-conventional models of Earth’s core. Use of antineutrinos to probe the deep interior of our planet is becoming practical due to recent fundamental advances in the antineutrino detectors.