The controversial idea that Earth has a nuclear reactor at its core (Discover, August 2002) may soon be put to the test. Physicists in Russia and the Netherlands have proposed using neutrino detectors to search for evidence of a five-mile-wide uranium ball at the planet’s center, churning out the heat that powers Earth’s magnetic field.
Neutrinos and their antimatter twins, antineutrinos, are lightweight, charge-free, nearly inert particles spit out by nuclear processes. If, as independent geophysicist J. Marvin Herndon argues, there is a “georeactor” at Earth’s core, it would emit vast numbers of antineutrinos. Because they react little with matter, antineutrinos usually zip through Earth unscathed. But they can be detected by a special type of apparatus: a huge tank of liquid in which rare antineutrino collisions with atomic nuclei produce faint but measurable bursts of light.
Researchers at the Institute for Nuclear Research of the Russian Academy of Sciences in Moscow and the Russian Research Center of the Kurchatov Institute have presented plans for a 1,000-ton detector at the Baksan Neutrino Observatory beneath the Caucasus Mountains. The scientists say their experiment could confirm the existence of the georeactor within a few years. Meanwhile, a team at the Kernfysisch Versneller Institute in the Netherlands advocates building a similar antineutrino detector below the Caribbean island of Curaçao. The site is more than 600 miles from the nearest nuclear power plant, which would simplify identifying antineutrinos from Earth’s core. “These proposals are a good example of how science should progress,” says Herndon. All they need now is about $50 million to become a reality.