Mapping the Earth's Engine
Science: Particle physicists and geophysicists rarely meet to compare notes, but earlier this year researchers from these two disciplines gathered to discuss antineutrinos (the antiparticle of the neutrino). These fundamental particles are a by-product of reactions occurring in nuclear reactors and pass easily through Earth, but they are also generated deep inside Earth by the natural radioactive decay of uranium, thorium, and potassium (in which case they are called geoneutrinos). Particle physicists have recently shown that it is possible to detect geoneutrinos and thus establish limits on the amount of radioactive energy produced in the interior of our planet.
