The Italian Almanac
Ghost-like particles long thought to arise from the churning magma around the Earth's core have been observed for the first time by scientists at an underground laboratory in central Italy. Published on Cornell University's online physics journal, arXiv.org, the study marks the first ever detection of geo-neutrinos, elusive particles that have almost no mass and move seamlessly through matter.
"This experiment is the beginning of a new era in our study of the mechanisms at work in the planet's interior," said Gianpaolo Bellini, who led the team of researchers at the Gran Sasso particle physics laboratory in Abruzzo. According to Bellini, geo-neutrinos are an offshoot of powerful reactions at the Earth's center that create enormous amounts of energy and give rise to many of the geological phenomena that shape the Earth's surface.
Apart from offering insight into the forces in play thousands of kilometers beneath our feet, he said studying geo-neutrinos could also help explain why disasters like earthquakes, volcanoes and tsunamis strike when they do. "Being able to observe these particles is like having a probe that goes into the center of the Earth".
Scientists have long suspected that the decay of radioactive elements in the Earth's core gave off neutrinos, but this is the first time they have ever "seen" one. Bellini's team spotted the particle using a neutrino-measuring device called a Borexino, the first of its kind, which was unveiled in August after eight years of development.
The Borexino's main job is to monitor neutrinos from the sun, which scientists last summer used to verify long-standing theories about its structure and composition. Bellini's team set out to glean the same kind of information about the insides of the Earth, though with the handicap of having a much smaller sample to work with. While the sun bombards the Earth with billions of neutrinos every day, the ones arising from the Earth's core are by comparison few and far between.
Until now, the main difficulty in observing neutrinos has been interference from other energy sources. The Italian team's first step towards reducing this interference was creating underground laboratories. These extend beneath the Gran Sasso mountain in central Italy, using the surface rock as an additional filter. However, the real breakthrough was the Borexino device, which took 100 scientists eight years to build.