Underground lab detects ghost particles from Earth's interior

Scientists have captured ghost particles, known as geoneutrinos, emerging from deep within Earth at an underground laboratory in a Canadian mine. The November detection of roughly 50 such particles marks the first successful observation in the Western Hemisphere. These findings provide a rare look at the radioactive decay processes that generate Earth's internal heat and drive geological movement. The data suggests radioactive materials might not be evenly mixed throughout the planet's mantle, challenging a long-held scientific view. If confirmed, this could reshape understanding of the forces beneath the crust.

The Canadian results join earlier detections from experiments in Japan in 2005 and Italy in 2009. The three experiments recorded different signal strengths, with Italy's being high, Japan's low, and Canada's falling in the middle. On the surface, this variation could indicate a higher concentration of radioactive material in the Western Hemisphere compared to the Eastern Hemisphere. However, scientists note the measurements come with significant uncertainty. Geochemist William McDonough of the Chinese Academy of Sciences has cautioned that it is unclear if the differences reflect Earth's true composition or limitations in the detection methods.

Radioactive decay of elements like uranium and thorium releases the heat that keeps Earth's core active and fuels the slow churning of rock in the mantle. This movement underpins geological activity, including volcanism and earthquakes. The planet's internal heat also influences the generation of its protective magnetic field. An uneven distribution of these heat-producing elements would mean some mantle regions generate more thermal energy than others, potentially affecting these global systems.

READ MORE: Scientists find common brain signal linked to schizophrenia symptoms

READ MORE: Water reacts with plastics to create harmful particles, study finds

For decades, the prevailing model assumed Earth's mantle was well-stirred over time, leading to a relatively uniform spread of radioactive material. "The results could offer a hint that the mantle isn't uniform," particle astrophysicist Mark Chen of Queen's University told Quanta Magazine. He suggested deep Earth structures might concentrate certain elements. This idea is intriguing given the known existence of two enormous, mysterious regions deep in the mantle near the core, one beneath Africa and another under the Pacific Ocean. Whether these structures relate to the new geoneutrino data remains unknown.

Geoneutrinos are produced by radioactive decay processes inside the planet and are famously elusive, earning the nickname ghost particles. They interact so weakly with matter that trillions pass through a human body every second without a trace. Detecting the minuscule fraction that do interact requires highly sensitive equipment buried deep underground to shield from other particles. The Canadian lab is situated more than a mile below the surface in an active mine. With only a few dozen geoneutrinos detected globally so far, scientists emphasize the need for more data to draw firm conclusions. A large new neutrino detector in China is expected to soon report its own results, which will provide a crucial point of comparison. This additional information will help researchers test whether the apparent hemispheric differences are real and begin to map the distribution of radioactive elements deep inside Earth.

With files from geekspin